Biology Module 2 (part 2)

monomer for protein

amino acid

monomer for carbohydrates

monosaccharide (single-unit sugar)

monomers for lipids

fatty acids and glycerol

monomers for nucleic acids

nucleotides

proteins are made of _____ which are ____

polypeptides, made of polymers (amino acids)

chemical bonds for lipids

ester bond

chemical bonds for proteins

peptide bonds

chemical bonds for carbohydrates

glycosidic linkage (covalent bond from dehydration synthesis)

chemical bonds for nucleic acids

phosphodiester linkages (covalent bonds that connect nucleotides)

R group

determine the chemical/physical properties of each amino acid

structure of amino acid

molecules with a carbon atom bonded to:
amino + carboxyl group, hydrogen atom, and R group

zwitterions

amino acids at ~7pH with a neutral charge (normal body pH)

• depronated carboxyl group

• pronated amino group

essential amino acids

cannot be produced from the body

non essential amino acids

can be produced from body

conditionally essential amino acids

can be synthesized from the body but only under certain conditions (stress/illness), the body may not produce enough

peptide bonds

covalent bonds that link amino acids together

primary structure

(polypeptide) chain of amino acids

secondary structure

folding of polypeptide backbone due to hydrogen bonds between atoms of the backbone

• alpha helix (coil) or beta pleated sheet (folded) structure

tertiary structure

3d shape of a single polypeptide chain

• (shape determined by these interactions)

  • hydrogen/ionic bonds, van der waals interactions, hydrophobic interactions, and disulfide bridges

quaternary structure

two or more polypeptide chains

chaperonins

proteins that assist in proper folding of other proteins (proper 3d structure)

denaturation

loss of protein structure due to environmental factors

sickle cell disease

single amino acid change in primary structure leading to altered protein structure and function

nucleic acid function

store, transmit, and help express hereditary information

protein function

defense, storage,transport, cellular communication, movement, and structural support

carbohydrates function

provide fuel and building material for cells

purines (in nitrogenous bases)

double-ring structures

• A and G

pyrimidines (nitrogenous bases)

Single-ring structures

• C, T, and U

DNA structure

double helix with two polynucleotide strands running antiparallel to another

DNA function

contains genetic blueprint and responsible for heredity

directs protein synthesis

RNA structure

single stranded (but can fold to 3d structure)

mRNA

carries genetic information from DNA to ribosomes for protein synthesis

tRNA

links mRNA codons to specific amino acids during protein synthesis

rRNA

major component of ribosomes

RNA function

plays various roles in gene expression and protein synthesis

gene expression

the process for which DNA is used to direct the synthesis of proteins

• DNA > RNA > Protein