Test 1: Biol 213
252 Cards in this Set
Front | Back |
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Scientists believe that all living cells today evolved from an ancestral cell that existed more than three _____ years ago.
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billion
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By definition, prokaryotic cells do no possess ______.
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a nucleus
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The _____ of an atom specifies the rules of chemistry by which atoms combine to form molecules.
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electrons
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When an electron jumps from one atom to another, two ions of opposite charge are generated. The ions can be held together by a mutual attraction known as
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ionic bond
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Table indicates the electrons in the first 4 atomic electron shells for selected elements. Which element will form ions with a net charge of +1 in solution?
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sodium, potassium
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Water molecules tend to stick to each other via
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hydrogen bonding
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Enthalpy can be defined as
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the heat content of a substance (H)
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The ultimate source of energy for most living organisms is
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the sun
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Antibody molecules (H & L chains) and spectrin molecules (a and B subunits) are examples of multiple peptide chains. The interactions that hold the polypeptide chains together are examples of
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quaternary structure
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The α-helix and
β-pleated sheet are examples of protein structures that are based on the formation of what type of bonds
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hydrogen bonds
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The R groups found in the amino acids shown below are examples of
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basic sidechains
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Two or three α helices can sometimes wrap around each other to form coiled-coils. The stable wrapping of one helix around another is typically driven by _____ interactions.
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hydrophobic
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A lipid is considered to be an amphipathic molecule because it
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interacts equally well with water and non-aqueous environments
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The rate of lipid diffusion in a biological membrane is
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similar to the rate of diffusion of small polar molecules in the cytoplasm
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The lipid component of biological membranes that has a relatively large hydrophobic region but a very small polar head consisting only of a hydroxyl group (-OH) is
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cholesterol
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Lipid flip-flop refers to
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the movement of lipid from one leaflet of a membrane to the other
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What causes yeast demise
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inability to import sugar into the cell
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Placing red blood cells in a hypotonic solution, where the salt concentration is much lower than normal, leads to
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cell bursting and loss of hemoglobin to create a cell ghost
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Each sodium channel in a cell's membrane can conduct 1 million sodium ions across the lipid bilary, making it very important to precisely regulate when it opens and closes. Opening of the sodium channel is triggered by:
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a change in membrane potential, binding of a chemical ligand to the extracellular domain of the ion channel & mechanical stress affecting the shape of the lipid bilayer
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(T/F) archae are more closely related to bacteria that eukaryotes.
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false
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Cell theory
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all living things are produced by replication of other cells
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Major disadvantages of electron microscopy
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samples must be dead, expensive equipment, requires great expertise
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All eukaryotic cells have
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a nucleus
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Subatomic particle that determines the atomic number and therefore the element identity?
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proton
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According to the chart, which elements are chemically inert?
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helium, neon
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How do protein, nucleic acid and polysaccharides molecules polymerize?
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dehydration synthesis
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What is the weakest type of bond?
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van der Waals
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Enzymes
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catalysts that lower the activation energy for a given reaction
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What is the ΔG for a reaction at chemical equilibium?
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0
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Chemical reactions that break down polymers into monomers
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catabolic
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What does the Km value roughly indicate with respect to enzyme substrate interactions?
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the enzyme-substrate binding affinity
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_____ is often used in anabolic reactions white _____ is used mainly for catabolic reactions.
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NADPH, NAD+
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Protein can be unfolded by a process called
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denaturation
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How does an allosteric inhibitor affect the active site of an enzyme?
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It binds to a second site, causing a conformation change in the enzyme that makes the active site less accommodating to the substrate.
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Large-scale study of proteins
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proteomics
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Why are a helices and B sheets common folding patterns in polypeptides?
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amino acid side chains are not involved in forming the hydrogen bonds, allowing different sequences to adopt those folding patterns.
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The α-helix and
β-pleated sheets are examples of protein ____ structure.
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secondary
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The nonpolar amino acids leucine, isoleucine and valine are conserved in the binding pocket of a particular class of proteins. What types of interactions might these residues be involved in?
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hydrophobic bonding (van der Waals)
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In a DNA double helix,
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the 2 DNA strands run antiparallel
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DNA helix 5'-GCAAGGCAGCAA-3' complentary strand?
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5'-TTCGCTGCCTTGC-3'
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prokaryotic
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simple structural org, complexity lies in molecular organization
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eukaryotic
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complex structural org.
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size range of a prokaryote
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0.1-10 µm
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size range of a eukaryote
their organelle size
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10-100 µm
2 µm
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mitochondria & chloroplasts examples of?
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endosymbiotic events
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what century was microscope invented
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17th
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Robert Hooke discovered ___, how?
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cells, in slice of cork, coined "cells" from medival monastery architectural term
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Antony van Leeuwenhoek
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discoveries in descriptions of protozoa, bacteria & many plants & animal cells, oral microbiology w/teeth crud sample
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18th century
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enlightenment, cells and microscopes were insignificant, quality of microscopes were poor
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Homunculus
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18th c microscope interpretation of human sperm cell
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Early 19th century
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advances in optical theory, construction of achromatic lense
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achromatic lens
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lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus in the same plane.
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Cell theory first formulation (2 things), by who?
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all organisms made of cells
-cell is fundamental unit of life
Mattias Schleiden & Theodor Scwann
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Cell theory refinement, by who?
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modern cells arise only by division of preexisting cells
Rudolf Virchow
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Late 19th century
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link cell biology to other biological processes
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apochromatic optics
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resolution/visualization at the theoretical limits of visible light optics
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ultracentrifuge
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allowed development of protocols of cell fractionation (separates parts of cell)
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Zernike
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phase contrast optics, high contrast images of LIVING cells w/o staining
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E.B. Wilson
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wrote The Cell in Development and Heredity, combining cells with genetics & embryogenesis
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After WWII (3 major developments)
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radioactive isotope labels (follow), electron microscope (see), electrophoresis (separate)
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1970s-Present
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molecular/genetics techniques, gene chips (expression of 1000s genes at once), genomics (study of gene sequence), proteomics (study of proteins)
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eukarya "crown group" kingdoms
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plantae, animalia, fungi
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why are/aren't viruses alive?
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has nucleic acid DNA OR RNA not both & proteins, doesn't metabolize
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why are/aren't viroids (plant parasites) alive?
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small pieces of naked RNA, no proteins
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why are/aren't prions alive
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strictly proteins
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central dogma sequence
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DNA synthesis/replication > RNA synthesis (transcription) > protein synthesis (translation)
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ionic bonds
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complete transfer of e-
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covalent bonds, strength?
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sharing of pairs of e-, strong: 80-100 kcal/mol E
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polar bond
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unequal sharing of pair
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non-polar bond
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equal sharing of electron pair
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polar covalent bonds display
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partial charges
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hydrogen bonds
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weak interactions, 2-5 kcal/mol E, collectively are strong
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hydrophilic molecules
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polar & ionic, readily dissolve in water
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hydrophobic molecules
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non-polar, usually insoluble in water
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hydrophobic interactions (van der Waals)
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interactions between molecules with non-polar covalent bonds, weak: 0.1-0.3 kcal/mol E
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4 macromolecules
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carbohydrates, lipids, proteins, nucleic acids
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monomers of polysaccharides, lipids, proteins and nucleic acids
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sugars, fatty acids, amino acids, nucleotides
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dehydration synthesis
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removal of 1 H2O to join monomers into polymer
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carbohydrates function
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energy storage (starch, glycogen), structural (cellulose, chitin, peptidoglycan, cell surface/signaling markers)
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hydrolysis
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adding H2O to break down polymer into monomer
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disaccharides
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maltose (glucose + glucose)
lactose (galactose + glucose)
sucrose (glucose + fructose)
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difference between α and
β glucose
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H and OH on carbon 1 are flipped
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difference between cellulose and starch
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carbon 5 is CH2OH on the top and OH the number 2 carbon on the bottom of all glucose monomers in starch, in cellulose it is alternating with CH2OH and OH on top and bottom of the carbon 5 and 2
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glycogen
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made by animals in liver, energy storage polymer
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cellulose
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structural polymer, hard to break down
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protozoan-termite relationship
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protozoan live inside termite, breaks down wood, anaerobic, put termites in pure O2 to kill them
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monomer of chitin
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N-acetyl glocosamine
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oligosaccharides
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non-repetitive sugar sequence
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lipids
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non-polar, hydrophobic compounds
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function of lipids
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energy storage (fats, triglycerides), structural (phospholipid membrane)
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fatty acid
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long, (mostly) ubranched hydrocarbon chains with single carboxyl group on the end, 14-20 carbons
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amphipathic
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hydrophilic end (carboxyl) and hydrophobic end (hydrocarbon)
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triglycerol
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glycerol + 3 fatty acids
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saturated fat
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no double bond in hydrocarbon chain
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unsaturated fat
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double bond in hydrocarbon chain
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What links glycerol and fatty acids by dehydration synthesis?
|
ester linkage
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phospholipid
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glycerol + 2 fatty acids + phosphate group (+polar group), highly amphipathic (phosphate, polar group and glycerol are hydrophilic, fatty acid is hydrophobic), self-sealing
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triaglycerols
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form large spherical fat droplets in cell cytoplasm
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micelle
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lipid molecules that arrange themselves in a spherical form in aqueous solutions, 1 layer of hydrophilic head and tail
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Phospholipid bilayer
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A double layer of phospholipid molecules that is the primary component of all cellular membranes
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how does soap clean
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Traps the bacteria in a soap micelle, then the water washes it away. The thing about this is that we don't need to kill the bacteria on our skin, because they get trapped in the micelle and slide of in the water
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cholesterol
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membrane component, 4 rung structure, mostly hydrophobic w/hydroxyl or ketone group at one end
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function of cholesterol, in eukaryotes or prokaryotes?
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membrane components of ONLY eukaryotes to stabalize fluidity, regulate animal hormones
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proteins
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macromolecules, high degree of specificity in functions, 10,000 different types
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protein monomer
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amino acid
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amino acid
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amphoteric - amino groupd (base) + carboxy group (acid)
+ side group (polar or non-polar)
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what is the polarity of an amino acid based on?
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its side chain
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folding of hydrophobic amino acids
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folded into core of protein
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folding of hydrophilic amino acids
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folded out to surface of protein
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what links amino acids? between which compounds?
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peptide bond, amino + carboxyl groups
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general structure of protein
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peptide backbone + amino end (N-terminus) + carboxyl end (C-terminus) + side chains
all linked by peptide bonds
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primary (1°) protein structure
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amino acid sequence, covalent peptide bond
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secondary (2°) protein structure
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- α-helix and β sheets
- NO side groups involved
- amino acids linked by hydrogen bonds
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tertiary (3°) protein structure
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3D conformation of R-group interactions including hydrophobic interactions (van der Waals), disulfide bridge, ionic bond
still ONE protein
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tertiary (4°) protein structure
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R-group association of SEPERATE and multiple proteins
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collagen
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protein that makes up hair, nails etc in animals, stretchy
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what structures (°) in proteins have strong bonds? weak?
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strong - 1°
weak - 2°, 3°, 4°
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what denatures proteins?
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increase in temp, increase [urea]
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chaperonin protein
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molecule that steers proteins along productive folding pathways, helping them fold correctly and preventing them from forming aggregates inside the cell
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conditions inside chaperonin
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limited hydrophilic environment--not much H2O or ions
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nucleic acid components
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1 - pentose sure (ribose/deoxyribose)
2 - phosphate group
3 - nitrogenous base
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nucleic acid function? monomer?
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storage and transmission of genetic info, nucleotide
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2 types of nitrogenous bases
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1. Purine
adenine
guanine
2. Pyrimidine
thymine
cytosine
uracil (only in RNA)
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is deoxyribose and ribose in which DNA or RNA?
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deoxyribose - DNA
ribose - RNA
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what bond links nucleotides? at which carbons?
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- phosphodiester bonds
- 5'-3'
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what is backbone of nucleic acid?
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sugar-phosphate, the bases change
|
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1 - deoxyribose
2 - ribose
3 - A, T, G, C
4 - A, U, G, C
5 - double
6 - single
7 - genetic info storage
8 - genetic info expression
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kinetic vs potential E
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kinetic - motion
potential - position
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bioenergetics
|
energy transformation in living organisms
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1st law of thermodynamics
|
conservation of energy - energy cannot be created or destroyed
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breaking bonds = releasing or gaining ____?
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releasing kinetic energy
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2nd law of thermodynamics
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events in universe have direction, E tend to proceed downhill from high E to low E states, in energy transformation there is a decreasing amount of energy available to do work
|
entropy
|
energy not available to do work "disorder"
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Spontaneous reaction
|
Reaction that occurs without a constant input of energy
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Gibbs Free Energy Equation
|
∆G = ∆H + (-T ∆S)
G = Free Energy
∆H = Enthalpy
∆S = Entropy
T = Absolute Temperature (Kelvins)
|
ΔG<0?
ΔG>0?
which one is favorable?
|
- exergonic "spontaneous"
- endergonic "non-spontaneous" needs energy of activation
ΔG<0
|
is EA in gibbs free energy budget?
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no
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energy of activation
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energy needed to start a reaction
|
catalyst, example?
|
reduces energy of activation, interacts with components but comes out unchanged
ex. enzymes: promote specific rxns
|
enzymes are ___ for reaction & substrate
|
highly specific
|
what happens in enzyme reaction
|
substrate binds to active site which changes shape of substrate and releases it
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current model of active site function
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induced fit
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active site
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center of catalytic function
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substrate
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reactants for a specific enzyme
|
2 types of enzyme inhibitors
|
competitive and non-competitive
|
non-competitive inhibitor
|
binds to opposite side of enzyme and changes shape of protein
|
Competitive Inhibitor
|
the binding of a ligand to an enzyme's active site to inhibit its function, do not produce product
|
Vmax
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saturated substrate
|
what does Vmax/2 help determine
|
[substrate]
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allosteric regulation
|
using kind of non-competitive inhibitor to regulate [ ] of molecules in a cell
Z controls amt of [X], if too high it turns off enzyme
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anabolic
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builds complex molecules from simpler ones, endergonic
|
catabolic
|
breaks down complex molecules into simpler ones, either for components or as energy release, exergonic
|
ATP
used for what type or rxns?
|
energy currency of cell, energetic
|
NAD+/NADH
which is oxidized/reduced?
|
electron carrier, redox cofactor
oxidized: NAD+
reduced: NADH
|
oxidation
|
loss of a pair of electrons
|
reduction
|
gain of a pair of electrons
|
coupled reactions
|
when an exergonic and endergonic reaction are coupled together so that the energetically favorable and the unfavorable reactions happen at the same time, in the same place
|
functions of membrane
|
compartmentalize, selectively permeable, signal detection, cellular interactions, surface for some reactions, energy capture/transduction
|
membranes allow
|
different environment inside than outside the cell
|
Langmuir Trough
|
creates 1 molecule thick membrane layer
|
what percent of a membrane mass is protein
|
50%
|
who created Fluid Mosaic Model of membrane structure? what is it?
|
Singer-Nicholson, bimolecular layer of lipids with proteins in globular form "floating in a sea of lipids"
|
Davson-Danielli Model of membrane structure
|
bimolecular layer of lipids coated with extended proteins
|
are lipids amphipathic?
|
yes, has hydrophobic and hydrophilic regions
|
what makes up a membrane
|
phospholipid bilayer + proteins + carbohydrates + cholesterol + glycolipids
|
sphingolipids, function?
|
amino alcohol, fatty acid carboxy group, critical component of brain cells, assemble/localize certain types of proteins
|
membrane carbohydrates percentage? components (types)? how are they bound? function?
|
- 10%
- lipids (glycolipids) + proteins (glycoproteins)
- covalenty
- cell-cell recognition and cell interaction w/environment
|
what side of cell are membrane carbohydrates located?
|
exterior face
|
membrane proteins percentage? types?
|
- 50%
- integral, peripheral & lipid-anchored
|
integral proteins, aka?
|
embedded in lipid layer, have hydrophobic region, aka transmembran
|
peripheral proteins
|
located on membrane surface, NO hydrophobic domains
|
lipid-anchored proteins
|
attached covalently to lipids, hydrophobic
|
3 membrane protein functions
|
transport, enzymatic activity, signal transduction
|
liquid crystal concept of membrane
|
lipids are aligned with one another in gel-like arrays, NOT rigid, components can slide past one another
|
_____ serves as buffer to prevent abrupt transition from gel to crystal states?
|
cholesterol
|
asymmetry of membrane
|
molecular composition of each half of lipid bilayer are different (in an out of cell)
|
types of protein mobility
|
freely mobile, anchored, pulled in specific direction, drift within boundaries
|
FRAP
|
fluorescence recovery after photobleaching method of measuring the membrane diffusion rate
|
Apical plasma membrane
|
regulation of nutrient and water intake
regulated secretion
protection
|
lateral plasma membrane
|
cell contact & adhesion
cell communication
|
basal membrane
|
cell-substratum contact
generation of ion gradients
|
passive diffusion
ex?
|
go down concentration gradient
osmosis/diffusion
facilitated transport
|
active transport
|
goes against concentration gradient
requires ATP, ion pumps
|
what types of molecules get through passive diffusion? ex?
|
small hydrophobic molecules
O2, CO2, N2, benzene
small uncharged polar molecules
H2. O, glycerol, ethanol
|
what types of molecules do active diffusion? ex?
|
large uncharged polar molecules
amino acids, glucose, nucleosides
ions
H+, Na+, K+, Ca2+, Cl-, Mg2+
|
plant in hypotonic, isotonic & hypertonic solutions
|
turgid - water enters cell
flaccid - water enters + leaves cell
plasmolyzed - water leaves cell
|
animal cell in hypotonic, isotonic & hypertonic solutions
|
lysed - cell bursts
normal
shriveled - water leaves cell
|
phagocytosis
|
eating food
|
pinocytosis
|
drinking liquid
|
receptor-mediated endocytosis
|
specific molecules are ingested, vesicle coated in pili
|
central catabolic pathway for most cells, ΔG=?, pathways?
|
glucose + O
2
> CO
2
+ H
2
O
-686 kcal/mol
glycolysis, krebs, ETC/oxidative phosphorylation
|
types of work for ATP phosphorylation
|
transport work phosphorylates transport proteins, mechanical work phosphorylates motor proteins, chemical work phosphorylates key reactants
|
glycolysis: where? budget? output?
|
cytosol
1 glucose, 2 ATP
2 pyruvate, 4 APT (net 2 ATP), 2 NADH
|
2 pathways after production of pyruvic acid
|
aerobic, anaerobic (fermentation)
|
anaerobic pathway after glycolysis; types?
|
alcohol - produces 2 ethanol + CO
2
lactic acid - 2 lactate (in muscles)
|
3 obligate aerobic organs
|
brain, kidney, heart
|
aerobic pathway after glycolysis
|
Krebs cycle
|
Krebs cycle, where?
|
mitochondrial matrix, CO2 produced
|
mitochondria structures
size?
|
outer membrane, intermembrane space, inner membrane, matrix
0.2 - 1 μm diameter by 1 - 4 μm long
|
mitochondria inner membrane
|
cristae (highly folded)
UNIQUE lipid & protein content
|
mitochondrial matrix contains ___ and ___
|
mitochondrial DNA & ribosomes
|
mitochondria protein vs lipid percentages
|
2/3-3/4 protein to 1/3-1/4 lipid
(mostly protein)
|
pleiomorphic
organelle ex?
|
changes shape, divides, fuse
ex. mitochondra
|
pyruvate shuttle
|
uses a fatty acid derivative (coenzyme A) as a carrier molecule to get across BOTH mito membranes
|
(1) pyruvate pathway to krebs
|
3 C =>
1 > CO2
2 > enzyme > acetyl coA
NAD+ reduced to NADH + H+
|
one turn of krebs cycle (per 1 acetyl coA)
|
1 ATP
3 NADH
1 FADH2
2 CO2
|
krebs cycle leads to
|
electron transport/oxidative phosphorylation
|
electron transport/oxidative phosphorylation, where?
|
release of E from e
collected, oxidation of reduced NADH and FADH2
electrons passed to O2 thru series of redox proteins (cytochromes) in ETC, coupled to ATP synthesis
inner mitochondrial membrane
|
glycogen
|
glucose polymer (storage), stored in liver
|
respiration per glucose molecule yields
|
2 ATP = 4 ATP (krebs) - 2 ATP (NADH mito shuttle doesn't apply to prokaryotes)
30 ATP = from 10 NADH
4 ATP = from 2 FADH2
6 H2O, 6 CO2
===> 36 (or 38) ATP total under ideal conditions, reality is 30 ATP
|
who does photosynthesis
|
plants, protistans (algae), cyanobacteria
|
process of photosynthesis? ΔG? 2 major linked pathways?
|
CO
2
+ H
2
O > glucose + O
2
ΔG= +709 kcal/mol endergonic
hill reaction, calvin cycle
|
Planck's equation, meaning of variables?
|
E = hc/λ
energy = planck's constant X speed of light / wavelength
|
energy of 1 mol photon
|
~42 kcal
|
Engelmann experiments
|
action/absorption spectrum
|
shorter wavelength=?
longer wavelength=?
|
stronger energy
weaker energy
|
chlorophylls have greatest absorbance at which wavelength
|
blue and red light (500 and 700)
|
chloroplast structures
|
outer envelope membrane
inner envelope membrane
thylakoids
stroma
|
thylakoids
|
stacks into grana, space inside sac is called lumen
|
stroma
|
chloroplast DNA, ribosomes, etc.
|
Hill reaction
what does it do? require? where?
|
"Z scheme" / "light reactions"; capture of light E converted to e- (bond) E
requires intact photosystems I and II with absorptive pigment
in thylakoid membranes (hydrophobic environment)
|
what does Hill reaction produce? from what?
|
ATP from ETC, electrons stripped from oxidation of H2O to produce O2 & e- used to reduce NADP+
|
calvin cycle, where? uses what enzyme?
|
fixes CO2 into sugar, requires ATP and reducing power
stroma of chloroplast
RUBISCO
|
inputs & outputs of calvin cycle
|
ATP + NADPH
=> ADP+P + NADP+ + CH2O (sugar)
|
inputs & outputs of light reactions
|
H2O + light => O2 + NADPH + ATP
|
3 phases of the calvin cycle
|
1. carbon fixation
2. reduction
3. regeneration of the CO2 acceptor (RuBP)
|
budget of photosynthesis per molecule of glucose
|
48 photons
18 ATP
36 ATP (12 NADPH)
6 O2 produced
=> costs 54 ATP to make a glucose
|
both mitochondria and choroplast ___
|
make ATP by same basic mechanism:
ETC active transport of H+ across a membrane making pH gradient
release of pH gradient coupled to ATP synthesis in special enzyme arrays
|
chemiosmosis
[H+] in mitochondria and chloroplast? what are gradients released thru?
|
mito - [H+] in intermembrane space is 104 higher than in matrix
chloro - [H+] in thylakoid lumen is 104 higher than in lumen
- released thru ATP synthase
|
ATP synthase
|
Spans the membrane and and allows H+ ions to pass through it
|
what is used to make ATP in plants
|
proton gradient and membrane potential
|
what causes plant to do photorespiration
|
severe (dry) environments, too much O2 accumulates in leaf space
|
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
|
ATP and NADPH
|
Where does the Calvin cycle take place?
|
stroma of the chloroplast
|
When oxygen is released as a result of photosynthesis, it is a direct by-product of
|
splitting water molecules
|
A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment?
|
blue and violet
|
Which statement describes the functioning of photosystem II?
|
The electron vacancies in P680⁺ are filled by electrons derived from water.
|
Which of the following are directly associated with photosystem I?
|
receiving electrons from the thylakoid membrane electron transport chain
|
Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be
|
to test for liberation of O₂ in the light.
|
In a plant cell, where are the ATP synthase complexes located?
|
thylakoid membrane and inner mitochondrial membrane
|
In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from
|
the stroma to the thylakoid space
|
Where are the molecules of the electron transport chain found in plant cells?
|
thylakoid membranes of chloroplasts
|
In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during
|
both photosynthesis and respiration.
|
What is the primary function of the Calvin cycle?
|
synthesize simple sugars from carbon dioxide
|
In a plant leaf, the reactions that produce NADH occur in
|
neither the light reactions nor the Calvin cycle
|
The NADPH required for the Calvin cycle comes from
|
reactions initiated in photosystem I.
|
Reactions that require CO₂ take place in
|
the Calvin cycle alone.
|
Photorespiration lowers the efficiency of photosynthesis by
|
3-phosphoglycerate molecules
|
Very low concentrations of detergent make membranes leaky to small molecules and ions without damaging proteins. In isolated mitochondria exposed to detergent, the molecules of the electron transport chain and of ATP synthase remain intact. Do you expect ATP synthesis to continue in the p…
|
No, because with a leaky membrane, H+ gradient cannot be maintained.
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The pH in the stroma of the chloroplast should be ____________ compared to the thylakoids due to the ____________.
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higher; higher concentration of hydrogen ions in the thylakoid
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If oxygen is unavailable, predict what happens to the citric acid cycle.
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it stops because the supplies of NAD+and FAD become depleted.
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Photorespiration in chloroplasts differs from cellular respiration in mitochondria in that ____________.
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ATP is required for photorespiration but is a product of mitochondrial respiration
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