College Biology Final

cell respiration definition

the process in which energy stored in food molecules is transferred to ATP

lewis acids

release electrons

lewis bases

absorb electrons

important lewis acids and bases

NAD+ --> NADH

FAD --> FADH2

two types of cell respiration

anaerobic and aerobic

anaerobic respiration

does not need oxygen, most ancient form, came before aerobic, 2 forms (glycolysis and fermentation)

glycolysis

1 glucose (6Cs) + 2 ATP --> 2 pyruvic acids (3Cs) + 4 ATP

-takes place in the cytoplasm

-2 ATP profit

-breaks glucose in half

fermentation

1 pyruvate (3Cs) --> 2C molecule waste products* + 1 ATP

-an add on to glycolysis

-used by yeast and some bacteria

*acetic acid (bacteria) or ethanol (yeast)

aerobic respiration

requires oxygen, occurs in mitochondria

four steps in aerobic respiration

oxidative decarboxylation, Krebs cycle, electron transport chain, chemiosmosis

CoA

coenzyme a

oxidative decarboxylation

2 pyruvates + 2NAD+ + 2CoA --> 2CO2 + 2 acetyl-CoA + 2NADH

Krebs cycle (citric acid cycle)

2 acetyl-CoA + 4NAD+ + 2FADH --> 4CO2 + 2ATP + 4NADH + 2FADH2

electron transport chain

-the basis is an enzyme complex called a cytochrome

(NADH or FADH2) + O2 --> electrons --> cytochromes --> low energy electrons + H2O

electron transport chain diagram

chemiosmosis

-process where bulk of ATP is produced

-occurs along the membrane folds of mitochondria

-2 active factors (H+ pumps and ATP synthase)

ATP synthase

proton gate, always open, binds ADP + P to create ATP

chemiosmosis diagram

photosynthesis stages

light phase and dark phase

light color

based on photon energy level, Ex: 700 nm = red

surface color

based on differential absorption of light by a surface, black absorbs all colors, white reflects all colors, other colors absorb everything but themselves

light phase photosynthesis

H2O + chlorophyll + light + ADP + P + NADP+ --> ATP + NADPH + O2

two stages of light phase

photosystem II and photosystem I

photosystem II

photosytem I

dark phase photosynthesis

6 CO2 + 6H2O + ATP + NADPH ---> glucose

pathways in dark phase photosynthesis

C3 (calvin cycle), C4, CAM (found in cacti)

C3 vs. C4 plants

C3 plants- cool weather grass, woody plants, some grains (wheat, barley, oats, rye)

-high water and CO2 needs

C4 plants- tropical or warm weather grass, palm trees, tropical grains (rice, corn, sorgum, millet)

-water efficient and low CO2 needs

electronegativity

the tendency for atoms to draw electrons toward themselves

electronegativity and covalent bonds

some atoms will "grab" the electron more in a covalent bond, some share it equally

polar molecule

have an uneven charge distribution while being electrically neutral, formed when atoms show strong electronegativity differences

non polar molecules

have even charge distributions, formed when atoms have similar electronegativity

ion

a charged atom or molecule

nucleus in an atom

contains protons and neutrons

atomic number

number of protons in an atom

atomic weight

protons plus neutrons

chemical bonding

process by which atoms becomes physically attached through electron exchange or sharing (involves valence electrons)

ionic bonding

transfer of electrons

covalent bonding

sharing of electrons

hydrogen bonding

a weak charge attraction between positive and negative charges

solute

a substance that is dissolved in a solute

solvent

the substance in which the solute is dissolved

reference solvent for polar molecules

water (H20)

reference solvent for non polar molecules

liquid fats (oils)

hydrophilic

loves water (polar)

hydrophobic

hates water (non polar)

acid

any molecule that releases a proton (H+) in water solution

base

any molecule that absorbs a proton in water solution

pH

a measure of the acidity or alkalinity of a water solution

pH 7

neutral

pH < 7

acidic

pH > 7

basic

buffer

any molecule that can act as an acid or base, minimizes pH shifts in solutions

definition of organic chemistry

the chemistry of carbon, hydrogen, and any atom that can replace a hydrogen around a carbon

number of bonds in a carbon containing molecule

four

hydrocarbons

nonpolar, consist entirely of C and H, building blocks of all other organic molecules

hydrocarbons functional group

methane

alcohols

polar, modified water molecules

alcohols functional group

special case of alcohols

waxes are large multicarbon alcohols that do not dissolve in water because they have large hydrocarbon tails

amines

polar, modified ammonia molecules, can be powerful bases

amines functional group

C-NH2

aldehydes and ketones

polar

aldehydes and ketones functional group

carbonyl

carboxylic acids

polar, weak acids

carboxylic acids functional group

esters

non polar, combination of an alcohol and a carboxylic acid, fats are special cases, formed by dehydration, responsible for scents and flavors

esters functional group

carbohydrates definition

polyhyrdoxy aldehyde or ketone, aka sugars

biologically important carbohydrates

have 3-7 Cs (triose, tetrose, pentose, hexose)

monosaccharides definition

single hexose units

disaccharides definition

two conjoined monosaccharides

glucose

monosaccharide

-universal cell food

-found in honey and maple syrup

fructose

monosaccharide

-found in all sweet fruit and corn

galactose

monosaccharide

-found in milk only

sucrose

disaccharide

-cane or table sugar

-composed of a glucose and a fructose

maltose

disaccharide

-found in dark grains

-composed of two glucoses

lactose

disaccharide

-found in mammal milk

-composed of a glucose and a galactose

hexose polymers

fructose: fructans

galactose: galactans

the 2 glucose polymers

two glucose polymers

starches and celluloses

starches

-animals (glycogen)

-plants (starch)

-purpose: glucose storage

-amylase: enzyme that breaks up glucose for use

celluloses

-purpose: structural material

-used by plants to build bark, wood, leaves, etc

cellulase

enzyme that breaks down cellulose into glucose, made by bacteria

lipids definition

esters that are made of an alcohol called glycerol and 1-3 large carboxylic acids (aka fatty acids)

glycerol

3 carbon alcohol

fatty acids

large 10-28 C carboxylic acids

basic lipid

mono acyl glyceride

saturated vs unsaturated lipids

saturated: no double bonds, solid

unsaturated: has double bonds, liquid

double bond in saturation

double bond has the potential to absorb hydrogen, double bonds create kinks that make it harder for molecules to stick together (liquids)

lipids biological significance

building blocks of cell membranes, used for long term energy storage, high energy density

carbs vs fats energy storage

carbs are used for short term energy short falls, fat is used longterm to prevent starvation

amino acid definition

monomers of proteins, all have the same generic structure

amino acid structure

R group can be anything

number of amino acids used by living things

20

three R group categories

nonpolar, polar uncharged, charged

charged R groups

can be negative or positive, can switch between neg and pos from pH shifts

dipeptides

two amino acids joined together by a peptide bond

peptide bond

proteins definition

amino acid polymers

three structural levels of proteins

primary, secondary, tertiary