Bio 111 Nucleic Acids and Proteins

central dogma

information storage, processing, and production of working molecules in our cells

nucleic acids

store and transmit information to make functional proteins

DNA

info storage

transcription

carries info from DNA to RNA

RNA

sends info

translation

read info to synthesize a chain of amino acids to form protein

protein

molecule that does the most work/jobs within a cell; made up of one or more polypeptides; functional molecule; organized into 4 structures

amino acids

building blocks that link into polypeptides to form proteins; monomers

polymers

linked monomers

polypeptides

formed by polymers

backbone of protein

made of an amino group (nitrogen), side chain, and carboxyl group

alpha carbon

central carbon atom in side chain, attached to R group and H

r group

part of the side chain that differentiates the amino acids from one another and grants them their diverse functional properties, they vary between each amino acid; attached to alpha carbon

peptide bond

covalent bond that links 2 amino acids together

dehydration synthesis

removed H2O so the peptide bond can be created

basic

amino acids that are positively charged

acidic

amino acids that are negatively charged

disulfide bridge

2 sulfurs linked together, occurs in the amino acid cysteine (when cysteine encounters another cysteine it drops H and creates a bond between sulfides)

positively charged

hydrophilic, basic

negatively charged

hydrophilic, acidic

primary structure

first level of protein structure; sequence of amino acids

N-terminus

terminal where amino acid sequence starts; free amino group

C-terminus

amino acid sequence ends at this terminal; carboxyl group

carboxyl group

COOH

amino group

free, not attached to anything, H2N (Nitrogen)

secondary structure

second level of protein structure; relies on hydrogen bonding between atoms of the backbone

a-helix

“alpha helix;” part of secondary structure; hydrogen bonds form between peptide chains; held together by hydrogen atoms of backbone

B-sheet

“beta sheet;” part of secondary structure; polypeptide chains

tertiary structure

third level of protein structures; determined by interactions between R groups and between R groups and their environment; ionic bonds, hydrogen bonds, dissulfide bridge, Van der Waals/hydrophobic interactions; 3D and contains multiple secondary structures

binding pocket

cavity in tertiary structure and is what gives protein function, if it loses shape, it loses function

quaternary structure

highest level of protein structures; exists when 2 or more polypeptides come together as subunits of a single functional protein; not all proteins have; stick the same way tertiary structures do

nucleic acids

strings of individual nucleotides each containing a 5’-carbon sugar, phosphate group, and nitrogenous base; information molecules; DNA and RNA

phosphate group

has lots of negative charges that interact with water

5’ carbon sugar

simple sugar with 5 carbons in its structure

nitrogenous base

building block of nucleic acids

hydroxyl

hydrogen atom covalently bonded to oxygen atom

DNA

polymer of deoxyribonucleotides; antiparallel double helix held together through complimentary base pairing; directionally runs from 5’ end to 3’ end

phosphodiester bond

bond between 3’ hydroxyl group and 5’ phosphate group; formed from dehydration synthesis; forms backbone of nucleic acids

antiparallel double helix

strands are flipped relative to one another

complementary base pairing

nitrogenous bases bond with corresponding partner (T=A, G=C in DNA)