AP Bio Semester 1

Polar covalent bonds in water molecules result in

hydrogen bonding

Water is a ___ molecule

polar

What does polarity alow water to do?

to form hydrogen bonds with each other

4 properties of water

- cohesive behavior

- ability to moderate temp

- expansion upon freezing

- versatility as a solvent

Cohesion

Hydrogen bonds between H2O molecules (sticking to itself)

Hydrogen bonds are ____ bonds

intermolecular

Adhesion

Hydrogen bonds between H2O & other polar moelcules (sticking to other things)

What is cohesion responsible for?

Waters

- high heat of vaporization

- high specific heat

- High surface tension

Transpiration

plants/trees ability to pull H2O molecules up

What does transpiration result from?

- cohesion

- adhesion

- evaporation

surface tension

force exterted by H2O molecules on the surface of a body of H2O

Surface tension creates

a kind of web or net upo the surface

Specific heat

the amount of heat that must be absorbed or lost for 1 gram of that substance to change its temp by 1 C

Specific heat of water

1 cal/ (g*C)

Why does H2O resist changing its temp?

Bc of its high specific heat

Heat of vaporization

the heat a liquid must absorb for 1 g to be converted to gas

Evaporative cooling

Helps stabilize temps in organisms & bodies of H2O

H2O is less dense as a

solid than as a liquid

Solution

liquid that is completely homogenous mixture of substances

Solvent

dissolving agent of a solution

Solute

substance that is dissolved

Why is water a versatile solvent?

bc of its polarity

Hydrophilic

likes H2O

Hydrophobic

hates H2O

Acid

increased H+ concentration

- less than 7 on pH scale

- the more H+ ions the more acidic

Base

decreased H+ concentration

- more than 7 on pH scale

- the less H+ ions (or more OH- ions) the more basic

Strong acids & bases dissociate completely in

water

Dissolved CO2 in seawater forms

carbonic acid

Ocean acidification

carbonic acid formed from dissolved CO2

As seawater acidifies, H+ ions combine with carbonate ions to...

produce bicarbonate ions

Carbon commonly bonds to

- carbon

- hydrogen

- oxygen

- nitrogen

What happens when carbon bonds to other carbons?

Results in carbon skeletons

Major elements of life

CHNOPS

Hydrocarbons

organic molecules consisting of only carbon & hydrogen

Hydrogen carbons can undergo reactions that release

a large amount of energy

Isomers

compounds with the same molecular formula but diff structures & properties

Structural isomers

have diff covalent arrangments of their atoms

Cis-trans isomers

have the same covalent bonds but differ in their spatial arrangements

Enantiomers

isomers that are mirror images of each other

Functional groups

Components of organic molecules that are most commonly involved in chemical reactions

7 functions groups that are msot important in chem of life

- hydroxyl group

- carbonyl group

- carboxyl group

- amino group

- sulfhydryl group

- phosphate group

- methyl group

Important organic phospate

ATP

ATP

adenine triphosphate

- stores the potential to react with water

Phosphate group

key for energy exchange

Methyl group

used to silence DNA (turn off genes)

Polar functional groups

- hydroxyl + carbonyl

- makes a molecule hydrophilic/H2O soluble

Carboxyl group

essential in amino acids

Amino group

essential in amino acids

Sulfhydryl group

important in protein structure

Carbohydrates

source of energy & provide sturctrual support

Nucleic acids

store genetic info & function in gene expression

Proteins

wide range of functions

- Catalyzing reactions

- transporting substrates into & out of cells

Lipids

group of diverse molecules that dont mix well with H2O

- make up cell membranes

- provide energy

- act as hormones

Monosaccharides

energy sources + building blocks

disaccharides

energy transfer

polysaccharides

- energy storage

- structures

Macromolecules

large polymers

Polymer

long molecules consisting of many simnilar building blocks

Monomers

repeating units that serve as building blocks

Examples of polymers

- carbohydrates

- proteins

- nucleic acids

Examples of macromolecules

proteins, nucleic acids, polysaccharides

Combine monomers to make

polymers

Dehydration synthesis

enzymes pull hydroxyl group off of 1 monomer & pulls hydrogen off the other

- The H & Oh combine to form H2O

Hydrolysis

Enzymes insert a H2O molecule between the monomers making up the polymer

Enzymes

Specialized macromolecules that speed up chemical reactions such as those to make or break down polymers

The covalent bond between 2 monosaccharides

glycosidic linkage

Starch

a storage polysaccharide of plabts, consists of glucose monomers

Glycogen

storage polysaccharide in animals (readily available glucose for the body)

Cellulose

polymer of glucose

- major component of tough wall of plant cells

Chitin

structural polysaccharide

- found in exoskeleton of arthropods

Fats

constructured from glycerol + fatty acids

Glycerol

3-Carbon alcohol with a hydroxyl group attached to each carbon

Fatty acid

consists of a carboxyl group attached to a long carbon skeleton

Saturated fatty acids

max number of hydrogen atoms possible & no double bonds

- solid at room temp

Unsaturated fatty acids

have 1 or more double bonds

- liquid at room temp

Phospholipid

2 fatty acids & a phosphate group attached to glycerol

Strucutre of phospholipid

- 3 hydrophobic fatty acid tails

- 1 hydrophilic head

Steroids

lipids characterized by a carbon skeleton consisting of 4 fused rings

Cholesterol

type of steroid

- a component in animal cell membranes & a precursor from which other steroids are synthesized

enzymatic proteins

selective acceleration of chemical reactions

defensive proteins

protect against disease

storage proteins

storage of amino acids

transport proteins

transport of substances

hormonal proteins

coordination of an organism's activities

receptor proteins

response of cell to chemical stimuli

contractile & motor

proteins

movement

structural proteins

support

Proteins are constructed from the same set of

20 amino acids

Polypeptides

unbranched polymers built from these amino acids

Peptide bond

bond between amino acids

Protein

Biologically functional molecule that consists of 1 or more polypeptides

Amino acids

Organic molecules w amino & carboxyl groups

Why do amino acids differ in their properties?

due to differing side chains, called R groups

4 levels of protein structure

- primary structure

- secondary structure

- Tertiary structure

- quaternary structure

Primary structure

genetically determined sequence of amino acids in a polypeptide chain

Secondary structure

involves interactions between carbonyl & amino groups in the polypeptide backbone

Tertiary structure

Interactions between amino acid side chains (R groups)

Quaternary structure

interactions between multiple folded tertiary polypeptides

Sickle cell disease

inherited blood disorder, results from a single amino acid substitution in the protein hemoglobin

Denaturation

loss of proteins native structure