GB1: Chapter 5B Flashcards
gene
amino acid sequence of polypeptide
nucleic acid/polynucleotides
polymers of nucleotides
Sugars in DNA/RNA
DNA: deoxyribose (lacks an oxygen at 2’C on ring)
RNA: ribose
dehydration synthesis/condensation reaction
covalently bonding 2 monomers together with a byproduct of water
hydrolysis
breaking covalent bond of polymer with input of water to create monomers
enzymes
specialized macromolecules that speed up chemical reactions
nitrogenous bases
adenine, guanine, cytosine, thymine (DNA), uracil (RNA)
Specific information carried in gene is encoded by specific sequences of nitrogenous bases
these determine amino acid sequence, as well as protein’s shape and function
nucleotides
composed of phosphate group, pentose sugar (DNA: deoxyribose sugar, RNA: ribose sugar), nitrogenous base
pyrimidine
1 six-sided ring of carbon and nitrogen atoms
cytosine, thymine, uracil
purines
1 six-sided ring fused to five-sided ring
adenine, guanine
Double helix
DNA has 2 strands of nucleic acids wound around an imaginary axis, held together by hydrogen bonds formed between paired nitrogenous bases
antiparallel
2 sugar-phosphate backbones run in opposite 5’ to 3’ directions
phosphodiester linkage
covalently bonds 2 nucleotides together through dehydration synthesis
[3’C OH group covalently bonded to phosphate’s H+ (that was attached to the OH group in water)]
ester linkage
covalently bonds 2 triglyceride/fat molecules together through dehydration synthesis
(the H+ of the hydroxyl of glycerol molecule covalently bonds to OH of fatty acids)
peptide bonds
covalently bonds 2 amino acids together through dehydration synthesis
[OH of C-terminus (carboxyl group) covalently bonds to H+ of N-terminus (amino group)]
complementary base pairing (w/ H bonds)
A - T (DNA): 2 hydrogen bonds
G - C: 3 hydrogen bonds
A - U (RNA): 2 hydrogen bonds
complementary base pairing allows DNA to be replicated for cellular division
RNA is special (with tRNA ex)
Single-stranded, so different RNA molecules can base pair, or even different regions on same RNA strand can. this allows for RNA to take on many shapes and thus have more functions
tRNA: there is complementary base pairing among nucleotides on tRNA that are antiparallel to each other
proteins
folded polypeptide(s) with specific functional final 3D shape
amino acids
monomer of proteins; organic molecule with amino group (n-terminus), carboxyl group (c-terminus), and r-group (side chain)
R-group (side chain)
physical/chemical properties of side chain dictates unique attributes of amino acid, contributing to how polypeptide functions
Types of R-groups
nonpolar - makes amino acid hydrophobic
polar: makes amino acid hydrophilic
charged: makes amino acid hydrophilic
+ = makes amino acid basic
- = makes amino acid acidic (usually acidic amino acids are - charged due to presence of carboxyl group that is usually dissociated at cellular pH)
polypeptide
long strings of amino acids bonded together, NOT a protein
structure of protein
primary
secondary
tertiary
quaternary
primary, secondary, and tertiary all occur simutaneously
quaternary only happens sometimes
primary structure of protein
polypeptides
secondary structure of protein
interactions between partial charges of amine (+) and carboxyl (-) groups forming hydrogen bonds in the backbone of polypeptide (not R-groups)
alpha helix and beta pleated sheet
alpha helix
delicate coil held together by hydrogen bonding between every 4th amino acid
beta-pleated sheets
2 or more segments of polypeptide chain lying parallel connected by hydrogen bonds between parts of the segments
tertiary structure of protein (3 types of interactions to make this)
gives overall shape of polypeptide due to interactions of side chains of amino acids, has to do with chemistry of R-group
hydrophobic interactions
ionic bonds
hydrogen bonds
disulfide bridges/sulfide bond
hydrophobic interactions in tertiary structure of protein
nonpolar regions experience van der waals/attraction through hydrophobicity
ionic bonds in tertiary structure of protein
can form between acidic and basic R-groups
hydrogen bonds in tertiary structure of protein
polar R-groups create charges, creating hydrogen bonds
disulfide bridge/sulfide bond in tertiary structure of protein
ONLY between 2 cysteine monomers that have sulfhydrl groups (-SH) - This keeps protein stable for longer
3 other influencers for protein folding
pH, salt concentration, temperature
function of carbohydrates
- breaks down sugar polymers into monomers to use as energy
6 function of lipids
- fatty compounds that give cell membranes structure
- filters what gets in/out
- absorbs vitamins
- makes hormones
- stores energy
- helps in cell communication
2 functions of nucleic acids
- storage/expression of genetic information
- genetic info can be passed down form one gen. to next
8 functions of proteins
- enzymes: catalyze rxns
- defense: protection against disease
- storage: stores amini acids
- transport: transports substances
- hormones: coordination of organism’s activities
- receptor: response of cell to chemical stimuli
- contractile: helps with movement
- structural: provides structural support
catalysts
chemical agents that selectively speed up chemical rxns but not consumed by rxn
sickle-cell disease
inherited blood disorder caused by substitution of 1 amino acid for a normal one in primary structure of hemoglobin (protein that carries oxygen in red blood cells). these sickle-shaped cells impede blood flow
denaturation
protein unravels and lose its original shape, biologically inactive
Gene expression
DNA directs RNA synthesis, RNA directs protein synthesis
