Final Exam

amino acids

organic compounds composed of nitrogen, carbon, hydrogen, oxygen

how many amino acids are there

20 amino acids

What are essential amino acids?

Amino acids that must be consumed because they cannot be created by the body

How many essential amino acids are there?

9

conditional amino acids

usually not essential, except in times of illness and stress

proteins

molecules made up of chains of amino acids

how many different proteins are at work in the body

over 100,000

enzymes

biological catalysts

T/F enzymes are a type of proteins

true

primary protein

sequence of amino acids

secondary protein structure

depends on the local interactions between parts of a protein chain

tertiary protein structure

the overall three-dimensional fold of protein
cross links, the attractions and repulsions

quaternary protein structure

protein consisting of two or more protein units
four polypeptide chains

peptide bond

amide bond

two amino acids are called

dipeptide

three amino acids are called

tripeptides

many amino acids are called

polypeptide

how do you name peptides?

-yl ending

N-terminal end

The end of a polypeptide chain with an -NH3+ group.

C-terminal end

the end of an amino acid chain with a -COO- group

What was the first protein to have its primary structure determined?

insulin
discovered by Banting and sequenced by Sanger

Structure of insulin

2 polypeptide chains linked by disulfide bond
Chain A with 21 chain B with 30

alpha helix

hydrogen bonds form between the oxygen of the CO groups and the hydrogen of NH groups
hydrogen bonds give the helical shape of a spiral staircase

Beta pleated sheet

hydrogen bonds form between carbonyl oxygen atoms and hydrogen atoms in the amide
bent sheet

triple helix

three polypeptide chains are woven together
strength typical of collagen, connective tissue, skin, tendons, and cartilage

fibrous proteins

consist of long fiber like shapes

alpha keratins

the proteins found in hair, hooves, nails, skin, and wool

beta keratins

feathers

globular proteins

compact, spherical shapes that fold up on themselves
carry out synthesis, transport, and metabolism

what is an example of a quaternary structyre

hemoglobin

protein functions

act as catalyst, transport, store, immune protection, generate movement, transmit

denaturation of proteins

involves the disruption of bonds in protein structures

what are the four different types of denaturing

heat and organic compounds, acids and bases, heavy metal ions, agitation

how do enzymes work

increase the rate of reaction by lowering the energy of activation

why are enzymes named?

identifies the reacting substance, describes the compound or the reaction, common name

how to name enzymes

-ase

what are the three factors that effect enzyme activity?

temperature, pH, inhibitors

How does temperature affect enzyme activity?

most active at 37 C
show little activity at low temperatures
at high temperatures over 50 C denature

How does pH affect enzyme activity?

most active at 7.4
certain organs require different pH

carbohydrates

major source of energy from our diet
made from carbon, hydrogen, oxygen

production of carbohydrates

produced by photosynthesis in plants
oxidized in living cells to produce CO2, H20, energy

Monosaccharides

consist of 3-8 Carbon chains in a carbonyl group
simplest sugar

Aldose

A carbohydrate whose carbonyl group is an aldehyde

ketose

A carbohydrate whose carbonyl group is a ketone

what is a aldopentose

five-carbon saccharide with an aldehyde group

how do you name a six carbon saccharide with a ketone group

ketohexose

structural isomers

Same molecular formula but different structural formula

stereoisomers

Compounds with the same structural formula but with a different arrangement of the atoms in space
cannot be completely matched

chiral

a molecule that is not superimposable on its mirror image

achiral

A molecule that is superimposable on its mirror image

chiral carbon atoms

a carbon atom, bonded to 4 different groups
non-superimposable mirror images

enantiomers

molecules that are mirror images of each other
must be chiral

how many enantiomers can a biological system have and why

only one that is active because it is the only one that can interact due to them not being achiral

Fischer projection

used to represent carbohydrates
vertical not horizontal

L

OH on the left

D

OH on the right

D-glucose

found in fruits
aldohexose
known as dextrose and blood sugar
building block

D-fructose

obtained from sucrose
monosaccharide
ketohexose
sweetest of the carbohydrates

D-galactose

aldohexose
not found in nature
obtained from the disaccharide lactose

galactosemia

enzyme needed to convert galactose into glucose is missing

hyperglycemia

the pancreas is unable to produce sufficient quantities of insulin

hypoglycemia

blood glucose level rises and then decreases rapidly to as low as 40
overproduction of insulin

normal blood glucose level

70-90

haworth structure

the ring structure of a monosaccharide

a isomer

OH below the ring

b isomer

OH above the ring

Oxidation of Monosaccharides

aldehyde group with an adjacent hydroxyl group creates carboxylic acid

sugar acids

produced by the oxidation of monosaccharides

naming sugar acids

-ose replaced with -onic acid

oxidation of fructose to glucose

Fructose, a ketohexose, rearranges to form glucose and is then oxidized in

Reduction of Monosaccharides

reduction of carbonyl group produces sugar alcohols (alditols)

reducing sugars

-ose ending to -itol
sweeteners in many sugar free products

disaccharide

consists of two monosaccharides linked together
combine in dehydration reaction

maltose

glucose + glucose
a-1,4 glycosidic bond
a-D-glucose

lactose

glucose + galactose
b-1,4-glycosidic bond
a-D-glucose + b-D-galactose

sucrose

glucose + fructose
a,b-1,2-glycosidic bond
a-D-glucose + b-D-fructose

sweeteners of sugar

sucrose is assigned at a value of 100

Polysaccharides

monosaccharides are joined together

amylose

straight chain of polysaccharides found in starch
a-1,4-glycosidic bond

amylopectin

branched chain
a-1,4- and a-1,6-glycosidic bonds

what makes up 20% of starch?

amylose

what makes up 80% of starch?

amylopectin

dextrins

smaller polysaccharides

glycogen

stored in the liver and muscle
provides energy between meals
highly branched

cellulose

structural unit of wood
b-1,4-glycosidic bonds
insoluble in water
cant be digested

lipids

biomolecules that contain fatty acids or a steroid nucleus
soluble in organic solvents not water

Are lipids soluble in water?

no, insoluble

Greek word lipos

fat

What rings do steroid nucleus have?

fused rings

What are the types of lipids

fatty acids and steroids

Steroids

do not contain fatty acids
four fused carbon rings

What structure are waxes, fats, oils, and phospholipids

esters

Why are lipids insoluble?

they have a large chain of carbons

Do steroids or fatty acids contain carbonyl groups?

Fatty acids

Fatty acids

unbranched carbon chains with a carboxylic group
12-18 carbon atoms
insoluble

saturated fat

no double bond

unsaturated fat

one or more double bond

is lauric acid saturated or unsaturated

saturated

where is lauric acid found

coconut

is myristic acid saturated or unsaturated

saturated