Chapter 1 Scientific method fig 1 2 Form a hypothesis A tentative explanation education guess Make an observation Make a prediction If then statements More observations Maybe from experiments could change of reject your hypothesis Meerkats Theory when you have LOTS of observations to support a hypothesis Guarding hypothesis Experiments Characteristics of life o o Introduce predator and note response vary social group size and predator type Introduce food and note response Water Bears tartegrade 1 5 mm long lack circulatory and respiratory system can reduce body water from 85 to 3 for up to 10 years how can you tell when they re alive at 3 body water o o o o Life is o Cellular respiration acquiring and using energy o Neuroactivity communication and interaction with external environment o Reproduction o o Evolution measured at population level over generations Structural complexity Cell the simplest self replicating entity that can exist as an independent unite of life o Contain and use information o Bounded surrounded by a plasma membrane fig 1 14 o Obtain and use energy from the environment Prokaryotic cell bacteria Eukaryotic cell yeast Protist a single cell eukaryte The unity and diversity of life are explained by evolution Evolution Organisms interact with each other and the environment Chapter 2 2 1 Properties of Atoms o Changes in the genetics of a population over time o There was a single origin of life and thus all life forms share some characteristics o New species arose by the divergence of populations over time Bacteria and archaeons look alike but archeaons have more in genetically common with eurkaryotes fig 1 17 Elements fundamental substances combined in various ways o Earth air fire water Atom basic unit of matter Atomic mass protons neutrons Atomic number protons Orbital a region in space where an electron is present most of the time Isotopes atoms of the same element that have different numbers of neurtrons Ions electrically charged atoms o Most of the time the electron is within the sphere but it s exact position at any moment is unpredictable o Max of electron in any orbital is 2 shell given energy levels where orbitals exist first shell can have a max of 2 all after can have a max of 8 all elements is a given row have the same number of shells and same number and types of orbitals all elements in vertical column are called a group family and have same number of electrons in outermost shell periodic table o o o Organic Molecules 2 Nucleic acids Store express and transmit genetic information Are polymers of nucleotides DNA RNA are the polymers made from nucleotides Nucleotides have 3 part structure Fig 2 18 o o Phosphate group Sugar Carbons in sugar are numbered with a prime 1 C covalently bonded to a base 5 C covalently bonded to a phosphate group o Nitrogenous base Single or double ring of C and N Variable part 2 kinds of bases pyrimidines single ring bases cytosine thymine uracile purines double rind bases guanine adenine RNA has O at 2 C DNA is missing an O at the 2 C Fig 2 18 Phosphate group of one NT connects to the 3 C of the next sugar Forms a phosphodiester bond series of covalent bonds Fig 2 20 o DNA o A strand is linear not branched o All the sugars in a strand have the same orientation 3 Carbohydrates CnH2nOn Simplest sugars monosaccharaides o Hexose 6C o Pentose 5C Glucose C6 H12 O6 Ribose C5 H10 O5 Deoxyribose C5 H10 O4 MS unbranched carbon chains form rings in an aqueous solution Fig 2 23 Polysaccharide MS linked together by covalent bonds Can be linear or branched if made from different MS Fig 2 24 4 Lipids contain lots of H and C nonpolar molecules insoluble in water hydrophobic 3 kinds of lipids o o o fats energy storage structural support steroids cholesterol and steroid hormones phospholipids make up bulk and form cell membranes Fats o Made up from fatty acids and glycerol Fig 2 25d o long chains of C and H with a carboxyl group at the end Fatty acids Saturated Cs linked by single covalent bonds Solid at room temperature Linear structure no bends or kinks Compact very close together Unsaturated one or more double bonds link C s Liquid at room temperature Bent kinked structure 3 fatty acids glycerol fat steroids Fig 2 27 four interconnected C rings ex cholesterol Key component of cell membranes Phospholipids Fig 2 28 o o o o A charged nitrogen containing molecule a phosphate group glycerol 2 fatty acids Why do plants store energy as carbs and animals store energy as fat Hypothesis o Relates to cell rigidity Cell walls of cellulose carb o Animals run alular respiration Break down carbs convert energy to ATP in mitochondria Fat is good for organ function Chapter 3 An information molecule must contain necessary information be passed to offspring be variable but still accurate DNA Structure Sugar Base nucleoside Sugar base phosphate group nucleotide can vary number of phosphate groups o o o o o o o o two nucleotides are linked by a series of covalent bonds called a phosphodiester bond fig 3 7 the DNA backbone alternates phosphates and sugars is the nonvariable part of DNA is negatively charged because of phosphate groups and sugars hydrophilic likes to interact with water the strand is linear all the sugars in a strand are oriented in the same direction the strand has a polarity direction can tell one end of the strand from the other because of consistent orientation Base sequence indicate orientation by using orientation of the sugar 5 C at the top 3 C at the bottom o Variable part of DNA o Where info is stored in sequence of bases o Strand base sequence order is unconstrained Nothing dictates the order of a strand Cellular DNA consists of 2 antiparallel strands in a double helix Fig 3 8 2 strands interact by H bonds forming between complementary bases 1 purine pairs with 1 pyrimidine keeps geometry of helix consistent o o base pairing rules allow you to compact and replicate o A T or G C Fig 3 9 Bases interact noncovalently with each other and stack or tightly group which stabilizes the helix Fig 3 10 Chapter 4 Primary structure Secondary structure the sequence of ss fig 4 4 Repeating folding patterns stabilized by H bonds between carbonyl group of 1 aa and the amide group of another nonadjacent aa R groups are not involved in the H bond formation BUT their shape and charge make secondary structures more or less likely in any particular polypeptide Alpha helix Each carbonyl group H bonds with an amide group 4 aa ahead in the chain fig 4 6 Beta
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