Chapter 2 Carbs, Lipids, Proteins

carbohydrates contain

C, H, and O in a 1:2:1 ratio

carbohydrates are classified according to

the number of sugar residues

monosaccharide

simple sugar

monosaccharide examples

glucose, fructose, galactose

disaccharide

two sugars

disaccharide examples

sucrose, lactose

polysaccharide

many sugars

polysaccharide examples

glycogen, starch, cellulose

lipids

made mostly of C and H

lipids are

mainly hydrophobic (non-polar)

types of lipids

fatty acids, eicosanoids, glycerides, steroids, phospholipids, glycolipids

fatty acids

long hydrophobic chains of C and H with a hydrophilic carboxylic acid group at one end

hydrophilic

polar

hydrophobic

nonpolar

fatty acids may be

saturated or unsaturated

saturated

all single covalent bonds

unsaturated

one or more double covalent bonds

monounsaturated

one double covalent bond

polyunsaturated

two or more double covalent bonds

glycerides

glycerol bound to fatty acids

monoglycerides

1 fatty acid

diglycerides

2 fatty acids

triglycerides/triacylglycerides

3 fatty acids

glycerides provide

insulation, protection, and function as energy store

steroids

cholesterol, cortisol, bile acids, hormones like testosterone, calcitrol, aldosterone

cholesterol

important in cell membranes, required for cell division, precursor to hormones and bile acids

cortisol

a hormone

phospholipids and glycolipids

diglycerides attached to either a phosphate group followed by a non-lipid group or a saccharide

phospholipids and glycolipids are part

hydrophilic and hydrophobic (fatty acid tails)

phospholipids and glycolipids in water produce

micelles with the hydrophilic heads facing water and the hydrophobic tails facing each other

proteins are

the most abundant organic molecules in an organism

proteins are composed of a

long chain of amino acids

how many amino acids are there

22

proteins contain

C, H, O, N and sometimes S

proteins may contain carbohydrates attached like

glycoproteins and proteoglycans

glycoproteins

small glycan groups, large protein

proteoglycans

large glycan groups, small protein

what functions do proteins play

support, movement, transport, buffering, metabolic regulation, coordination and control, defense

support

structural proteins

movement

contractile proteins

transport

channel and carrier proteins

buffering

all proteins help regulate pH with their free amino and carboxyl groups acting as weak acids and bases

metabolic regulation

enzymes

coordination and control

hormones

defense

antibodies

amino acid structure

amine group, central carbon, carboxyl group, R group

primary structure

sequence of amino acid chain

secondary structure

alpha helix or beta/pleated sheet

what forms the secondary structure

hydrogen bonds that fold the amino acid chain

tertiary structure

coiling of the secondary structure

quaternary structure

protein subunits that generate larger complexes to create it

the final structure and shape of a protein is based on

the amino acid sequence

enzymes are

catalysts that lower the activation energy of a reaction

are enzymes used up in a reaction

no they are recycled and reused

enzymes are very

specific and preform certain activities

when enzyme activity reaches a maximum rate it

saturates

inappropriate temperature or pH conditions

destroy hydrogen bonds and may denature enzymes and prevent their functions

enzyme substrate complex

when the substrate binds to the active site

nucleotides

large organic molecules found in the nucleus that store information and energy

nucleotides include

DNA and RNA

DNA

determines inheritance, contains information for all proteins in the body

RNA

an intermediate in synthesis of an individual protein

structure of a nucleotide (adenosine)

phosphate group, sugar, nitrogenous base

purines of DNA/RNA

adenine, guanine

pyrimidines of DNA/RNA

cytosine, thymine (DNA), uracil (RNA)

process of DNA to RNA

transcription

process of RNA to protein

translation

nucleotides such as ATP or GTP can be used to

store energy

the covalent bond between ADP and the third phosphate is a

high energy bond that is relatively easy to break, releases a lot of energy

ATPase catalyzes

dephosphorylation or decomposition of ATP to ADP