LIFE 102:Chapter 1-6
105 Cards in this Set
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Uniformity
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Exhibited mostly at the molecular and cellular level
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Diversity
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Exhibited mainly at the organismal level.
cell structure: Prok vs Euk
# cells: unicellular vs. multicellular
the way organisms acquire food: autotrophs vs. heterotrophs
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Scientific Method
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1. Question
2. Hypothesis
3. Experiment
4. Accept or reject hypothesis
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Organism is alive
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Metabolism
Growth and developement
Reproduction
Response to environment
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Living Matter consists of 25 elements
96% of living matter is (bulk elements):
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(H)ydrogen
(O)xygen
(N)itrogen
(C)arbon
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Trace elements
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Necessary in small amounts
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Atom
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The smallest possible particle of an element. It is made up of protons, electrons, and neutrons.
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Atomic Number
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Number of protons. Determines the element.
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Atomic weight
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#protons+number neutrons.
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Ions
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Atoms with extra or missing electrons. This gives a positive or negative charge.
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Isotopes
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atoms with same number of protons but different number of neutrons. If unstable, are radioactive.
Carbon isotopes differ in number of neutrons.
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Valence shell
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Outer shell. # of electrons in valence determines an atom's chem behavior. Full means stable
H needs 1 electron to fill valence
O needs 2
N needs 3
C needs 4
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compound
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a molecule made of 2 or more elements
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Covalent bond
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Strong bond sharing electrons. Single: one pair shared, Double: two pairs shared.
Polar: when one of the atoms attracts the electron pair more strongly. Ex water is polar, oxygen attracts electrons more than the hydrogen.
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Ionic bond
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Strong bond betw atoms when electron is transferred from one atom to another. Both atoms become charged ions--one positive(cation) and one negative (anion).
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Hydrogen bond
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Weak bond formed by electrical attraction betw a hydrogen atom and polarother atom(usually O or N).
Important for biology because: stabilizes large molecules(DNA, proteins) or for temporary associations betw molecules (signaling).
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Mass conservation law
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All atoms of the reactants are still present in the products.
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Chemical equilibrium
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the forward and reverse reactions occur at equal velocity. Same rate
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Electronegative elements
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Readily acquire electrons to become - ions
(right side of periodic table)
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How to distiguish one element from another?
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By their atomic number ( number of protons)
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How do atoms share electrons?
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Covelant bonds. Valence shells are filled
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Reversible reaction
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when there is chemical equilibrium
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Polar Molecule
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molecule with an unequal distribution of electrons. example water
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Water is a polar molecule. Why?
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The hydrogen end has a slightly positive charge while the oxygen end has a slightly negative charge.
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What type of bonds do water molecules form with each other
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hydrogen bonds
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Properties of water
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1. Cohesive: molecules stick together because of hydrogen bonds betw molecules. High surface tension
2. High specific heat: takes a lot of energy to increase temp
3. High heat of vaporization: takes a lot of energy to vaporize water
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Concentration
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number of solute molecules per unit of solvent
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Solute
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Compounds being dissolved
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Solvent
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Liquid, usually water
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Why is water a good solvent?
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Because it is polar. Hydrophilic compounds love water.
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pH range 0-14
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Neutral ph7 (water)
acidic <ph7 higher H+
basic ph>7 lower H+
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How many H+ in pure water?
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10^-7 M
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pH (formula)
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pH= -log [H+]
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Buffers
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weak acids/bases that can take up or donate H+
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How does a base affect H+ conc in a solution?
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Takes up Hydrogen because it is lower H+. pH will increase, overall H+ will lower.
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organic molecule
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carbon-containg molecule
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Why is carbon a good building block?
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it is tetravalent. Can make 4 chemical bonds.
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Variations in the carbon skeleton
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Length
shape (branched or not, rings
number and position of double bonds
side groups
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Butane and 2- Methylprobane (isobutane)
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both are C4H10, but vary in branching
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Side groups
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...
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Carboxy group
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Carboxylic acids are acidic because of the hydrogen in the -COOH group
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Amino group
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C-NH2 acts as a base because the nitrogen atom will draw an H+ (proton) to it
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Isomer
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Carbon compounds with same atomic composition but different structures and properties
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Types of isomers
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Structural have different carbon skeletons
Geometric have different spatial arrangement of the side groups next to a double bond
Enantiomers have different spatial arrangement of the side groups around an asymmetric carbon atom. Important for drugs
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4 types of macromolecules
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polysaccharides
lipids
proteins
nucleic acids(DNA,RNA)
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polymers
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very large molecule made of a chain of monomers
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Dehydration Synthesis
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Also condensation. Monomers are linked together to form a polymer and water is split off.
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Hydrolysis
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Reverse of dehydration. Polymers are split into monomers and water is released.
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Polysaccharide functions
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Fuel and building material
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1) What is the sugar monomer called?
2) What are two linked sugar monomers called?
3) What are three or more linked sugar monomers called?
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1) Monosaccharide
2) Disaccharide
3) Polysaccharide
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What atoms make up glucose ring
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5 carbon 1 oxygen
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Lipid characteristics
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hydrophobic
Not polymers
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Which macromolecule is not a polymer?
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Lipid
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Function of fats
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energy storage
insulation
protection
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Unsaturated fats
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One or more double bonds. Rigid so can't pack close enough to be solid
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Saturated fats
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no double bonds, solid. Saturated with hydrogen
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tryglyceride
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composed of three molecules of fatty acid joined to one molecule of glycerol
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What are the components of a phospholipid?
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Glycerol coupled to a phosphate group and two hydrocarbon. Hydrophilic head, hydrophobic tails
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Why do phospholipids form bilayers?
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The hydrophilic head associates with water and the hydrophobic fatty acid tails associate with one another
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Where's the amino acid?
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...
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Amino acid
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Has a nitrogen bonded to two hydrogens and the carbon skeleton
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How do you know if an amino acid is polar, non-polar, or electrically charged?
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~Look at the R-group. If there are only carbon hydrogen bonds, then it's non-polar. If there are charges on the r-group, then it is electrically charged. If there are bonds other than carbon-hydrogen, then it is polar
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peptide bond
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created by dehydration synthesis between 2 amino acids.
-special type of covalent bond.
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Protein Shape
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Primary structure: sequence of amino acids
Secondary Structure: H bonds form between different parts of polypeptide chain
Tertiary Structure: folding as a result of interactions between r groups form functional domains
Quaternary Structure: Soem proteins are made up of more than one po…
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primary structure
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the sequence of amino acids in a polypeptide chain, similar to the sequence of letters that spell out a specific word
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Secondary structure
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Coils and folds in patterns causing shape. Result of hydrogen bonds between atoms. Alpha helix or betapleated sheet
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tertiary structure
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interactions between side chains of various amino acids.
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Quaternary structure
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overall protein structure results from coming together of polypeptide subunits.
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How is the shape of a protein stablilized?
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Hydrogen bonds
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Disulfide bridge
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Hold a folded polypeptide together
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ionic bond
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occurs when a cation bonds to an anion
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protein denaturation
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the breakdown of proteins that permanently alters their biological activity and which can be caused by excessive heat
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Protein functions
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Enzymes
antibodies
structure
transport
cell communication
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Nucleotide
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5C sugar ring
phosphate
amino base
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RNA vs DNA: RNA
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= is single stranded, has Uracil instead of Thymine, & 2' extra OH on ribose
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Deoxyribose
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the sugar that makes up the "backbone" of the DNA with phosphate
part of nucleotide
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ribose
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the five-carbon sugar in RNA.
Extra O compared to deoxyribose
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Base-pair rule
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Each base pairs with its complementary base
A always with T(or U), G with C
Purine(AGony) always base pairs with pyrimidine
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Complementary
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If you know nucleotide sequence of one strand, you know that of the other
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Antiparallel
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one side of the double helix is facing upwards and the other side is facing the opposite way.
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Prokaryotic vs. Eukaryotic organism
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Eukaryotic
Has membrane-enclosed organelles (the largest which is usually the nucleus)
Prokaryotic
Simple/smaller
DOES NOT contain a nucleus or membrane enclosed organelles
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Why are eukaryotic compartmentalized?
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Organization, different chemical reactions can take place without interfering with each other
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Nuclear Envelope
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...
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Nuclear Pore Complexes
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govern passage of materials in and out of the nucleus ( large proteins, ribosome subunits, mRNA, and tRNA)
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Ribosomes
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Protein factories, where messenger RNA is translated into proteins
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Ribosomes
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Protein factories, where messenger RNA is translated into proteins
Float around in the cytosol or attached to ER
Both euk and prok have them
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Ribosomes
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Protein factories, where messenger RNA is translated into proteins
Float around in the cytosol or attached to ER
Both euk and prok have them
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Endoplasmic Reticulum
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A cellular structure consisting of a complex network of fine, branching tubules and interconnected folded membranes.
Sythesizes lipids
Produces proteins
Most ER products transferred to golgi app
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Golgi Apparatus
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A stack of flattened, membrane-bound compartments that performs three overlapping functions: secretion, processing, and protein sorting
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Where do proteins go after the golgi?
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Excreted through plasma membrane, to the plasma membrane itself, lysosome/vacuole through vesicles
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How are cell contents moved?
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Transferred in vesicles
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Lysosome
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Animals. breakdown of macros/organelles.
Autophagy: Recycling old cells.
Programmed cell destruction
Phagocytosis: digestion of particles taken up by the cell. Important or immune system
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Vacuole
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Plants
Sturdiness
storage of metabolites
sequesters toxins
stores compounds like poisons
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Why are lysosome products separated?
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To not damage rest of the cell
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Endomembrane System
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The ER+all structures that receive their components from the ER.
nuclear envelope
ER
Golgi app
vacuole
plasma membrane
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Not part of Endomembrane system
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Receive their components from cytosol
Peroxisomes
Mitochandria
Chloroplasts
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Structure & Function of Mitochandria
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Structure - 2 membranes that contain their own ribosomes and DNA (can make its own protein)
Function - converts glucose to energy (sugar to ATP)
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Structure and function of chloroplasts?
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1. Organelles specilalized for photosynthesis
-Stroma – the liquid part of the chloroplast
-Thylakoids – structure and function
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Endosymbiont Theory
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That mitochondria and plastids were formerly small prokaryotes (bacteria) that began living within larger cells
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What are the 3 types of cytoskeletal fibers?
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1. Intermediate filaments(Intermed)
2. Microtubules(thickest)
3. Microfilaments(Thinnest)
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Microtubules
Functions
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Cellular support
Tracks for organelle/vesicle mobement (take the tube)
Make spindle during cell division
Make flagella and cilia for cell movement
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Microfilaments functions
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Contractoin of cells
Muscle contraction in animals
Support for cellular projections
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Intermediate Filaments functions
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Heavy duty support
Reinforce cell shape and nuclear shape
Fix organelle position
More permanent, strongest
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Extracellular Matrix
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Meshwork of macromolecules outside plasma membrane
Support and anchorage for cells
involved in interaction between cells and signalling to cells
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Contact point types Animals
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1. Tight juntions:hold cells together and block transport of fluid betw cells.Keeps stuff out of body
2. Desmosomes:hold cells tog but don't block transport of fluid betw cells.Anchor cells to each other.
3. Gap junctions: Compounds transported from one cell to another. only small compo…
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