biochem exam 1

Macromolecules are made of

Smaller molecules

Macromolecules make up

Organelles

Living organisms are made of ______

Macromolecules

Biological information must be _______ from one generation to the next

Transmitted

Most abundant elements found in biological systems

Carbon, nitrogen, oxygen

Why is carbon most abundant in living systems

4 valence electrons (reactive), common, forms covalent bonds, can form complex backbones

Functional group

a small group of atoms that determine the properties of organic compounds

4 types of bio molecules contained in cells

Amino acids, carbohydrates, nucleotides, lipids

Amino acids contain

Alpha carbon, amino group, carboxylic acid group, side chain (R), hydrogen

Number of unique amino acids

20 (dependent on side chain)

Carbohydrates are

Monisaccharides or sugars, major type of biomolecule

Chemical formula of carbohydrates

(CH2O)n

N= # of carbons

Nucleotides contain

Five carbon sugar, nitrogenous base, phosphate group

amine

alcohol

-OH

thiol

-SH

ether

aldehyde

ketone

nucleotide components

pentose sugar, nitrogenous base, one or more phosphates

deoxyribonucleic acid

lack second OH group

pyrimidines (6 membered rings)

cytosine, thymine, uracil

purines (6 membered rings + 5 membered ring)

guanine, adenine

all nitrogenous bases can participate in _____________

acid base reactions

nucleosides

include a pentose sugar and nitrogenous base

adenine

guanine

thymine

cytosine

uracil

nucleotides are involved in

energy transduction, intracellular signaling, regulation of enzyme activity

how are nucleotides connected

phosphodiester bonds

incorporated nucleotides are known as

residues

phosphates are largely

negative

nucleotides make ____ macromolecules

polar

phosphate forms _____ bond between C3’ and C5’

ester

DNA is _________ as a single strand

unstable

DNA is oriented

antiparallel

complementary base pairs are connected through

hydrogen bonds

chargaffs rule

A+G=C+T

amount of A = amount of T

adds to 100

double stranded DNA twists into right-handed ______ organization

helical

driven by the hydrophobic effect

what makes up the backbone of the exterior helix

phosphate-sugar

diameter of helix

20 A

structural stability of DNA _______ heavily depend on hydrogen bonding between base pairs

does not

structural stability of DNA depends on

stacking interactions between adjacent base pairs

G/C pair is _____ than A/T pair

stronger

what can be used to determine if DNA is G/C or A/T rich

melting temperature (denaturation)

what happens if denatured DNA is cooled too quickly

abnormal base pairing can occur

RNA

single stranded, monomer= nucleotide, pentose sugar=ribose, bases= A,C,G,U

DNA

double stranded, pentose sugar=deoxyribose, bases=A,C,G,T

RNA can form _________ because of flexibility

RNA-DNA hybrid

essential for converting genetic code into proteins

mRNA, tRNA, rRNA

gene

unique sequence of nucleotides that act as the instructions for producing a specific polypeptide or RNA

central dogma of molecular biology

DNA→(transcription)→RNA→(translation)→Protein

the ideal biological solvent

water

water can dissolve…

ionic and polar solvents

non-covalent bonds are

additive

translation is the process of

protein synthesis - converts the language of nucleotides into the language of amino acids

transcribed RNA

mRNA

base triplet

a sequence of 3 nucleotides that correspond to 1 amino acid

codon

a 3-base sequence in mRNA

anticodon

a sequence of 3 nucleotides forming a unit of genetic code in a transfer RNA (tRNA) molecule

mutation

a heritable change in someones DNA sequence, includes insertions, deletions and substitutions

translation

genes → proteins

coding strand

5’→3’ (non-template)

non-coding strand

3’→5’ (template) complementary sequence to RNA

RNA

5’→3’ contains UGCA

RNA transcipt is complementary to the ________ strand

template (noncoding)

eukaryotic gene structures

open reading frame, contains introns and exons

prokaryotic gene structure

contain operon regions

RNA transcripts correspond to

a single functional unit (ex: a single polypeptide)

introns

intervening sequences, removed during processing

exons

expressed sequences, maintained during processing, contain necessary nucleotides

promoter

DNA sequence near beginning of the gene where polymerase binds to initiate transcription

terminator

DNA sequence that marks end of gene

actual faction of protein-coding sequences of DNA is small (1.5%) due to abundance of _____ and ________

introns and non-coding RNAs

chromatin

DNA and protein components of chromosomes

chromatin includes

nucleosomes and linker DNA

protein + DNA

nucleosome

cluster of proteins

histone core

8 histone proteins and linker DNA

euchromatin

less compact (active gene expression)

heterochromatin

more compact (inactive gene expression)