biochemistry

Question 1

how is a covalent bond formed

Answer 1

when unpaired electrons are shared

Question 2

what is a redox reaction

Answer 2

electrons transferred from one molecule to another

Question 3

what is oxidation

Answer 3

loss of electrons

Question 4

what is reduction

Answer 4

gain of electrons

Question 5

what is an exergonic reaction

Answer 5

delta g negative

occur spontaneously

Question 6

what is an endergonic reaction

Answer 6

delta g positive

cant occur spontaneously

Question 7

what is coupled to allow many reactions in the body to occur

Answer 7

an unfavourable reaction (positive delta G) and a favourable one (negative delta G) such as breakdown of ATP and H2O

Question 8

what is metabolism

Answer 8

all the reactions taking place in the body

Question 9

what can metabolism be divided into

Answer 9

catabolism and anabolism

Question 10

what is catabolism

Answer 10

breadking down complex molecules into smaller ones

releases energy

Question 11

what is anabolism

Answer 11

synthesising complex molecules from smaller ones

consumes energy

Question 12

what is an acid

Answer 12

proton donaters

Question 13

what is a base

Answer 13

proton acceptors

Question 14

what does the strength of an acid depend on

Answer 14

how readily it donates a proton

Question 15

how is acid strength measured

Answer 15

the acid dissociation constant, Ka

Question 16

what is the equation for pH

Answer 16

pH = -log10[H+]

Question 17

what is the Henderson-Hasselbalch equation

Answer 17

ph = pka + log [base]/[acid]

Question 18

what is a buffer

Answer 18

a solution used to control the ph of a reaction mixture

Question 19

when does ph = pka

Answer 19

when the [acid] is equal to the [conjugate base]

Question 20

what is the primary structure

Answer 20

one dimensional, the sequence of amino acid residues

Question 21

what is the secondary structure

Answer 21

the localised conformation of the polypeptide backbone

Question 22

what is the tertiary structure

Answer 22

the 3D structure of an entire polypeptide

Question 23

what is the quaternary structure

Answer 23

the spatial arrangement of polypeptide chains in a protein with multiple subunits

Question 24

what bond holds secondary structures together

Answer 24

hydrogen

Question 25

what are the 3 types of secondary structures

Answer 25

alpha helix beta strands and sheets triple helix

Question 26

where is the collagen triple helix found

Answer 26

bone and connective tissue

Question 27

how is a collagen triple helix formed

Answer 27

three helical chains twisted around each other to form a right handed superhelix

Question 28

what is the superhelix in the collagen triple helix called

Answer 28

tropocollagen

Question 29

what are the two types of tertiary structure

Answer 29

fibrous and globular proteins

Question 30

name two fibrous proteins

Answer 30

collagen and keratin

Question 31

name two globular proteins

Answer 31

myoglobin and haemoglobin

Question 32

what type of protein is water soluble

Answer 32

globular

Question 33

what can denature a protein

Answer 33

heat ph a variety of chemicals

Question 34

what is a sugar and a base called

Answer 34

nucleoside

Question 35

what makes up a nucleotide

Answer 35

phosphate sugar base

Question 36

what end can new bases be added to in a growing DNA strand

Answer 36

3 prime

Question 37

what enzyme adds new bases to a growing dna strand

Answer 37

DNA polymerase

Question 38

what bond forms between bases in dna strands

Answer 38

hydrogen

Question 39

what type of process is dna replication

Answer 39

semi conservative

Question 40

what is rrna

Answer 40

ribosomal rna - combines with protein to make ribosomes

Question 41

what is trna

Answer 41

transfer rna - carries the amino acids to be incorporated into the protein

Question 42

what is mrna

Answer 42

messenger rna- carries the genetic information for protein synthesis

Question 43

what determines what amino acid will bind to a specific trna

Answer 43

anticodon sequence

Question 44

how is transcription initiated

Answer 44

rna polymerase binds to promotors on DNA

Question 45

what enzyme separates dna strands

Answer 45

helicase

Question 46

what enzyme binds AA to their tRNA

Answer 46

aminoacyl-tRNA synthetases

Question 47

what enzyme catalyses formation of peptide bonds between amino acids

Answer 47

peptidyl transferase

Question 48

what moves the ribosome along mRNA

Answer 48

EF-2 (elongation factor)

Question 49

what is a point mutation

Answer 49

change in a single base in dna

Question 50

what is a missense mutation

Answer 50

change of amino acid sequence

Question 51

what is a nonsense mutation

Answer 51

creates a new termination codon, changes protein due to premature stop

Question 52

what is a silent mutation

Answer 52

degeneracy of genetic code, no effect on amino acid sequence or protein function

Question 53

what is a frameshift mutation

Answer 53

addition or deletion of 1 or 2 bases, changes triplets, amino acids and protein

Question 54

what is vmax

Answer 54

the maximum rate of a reaction

Question 55

what is the michaelis constant

Answer 55

Km - the substrate conc where the initial reaction rate is half vmax

Question 56

where is vmax on a graph

Answer 56

intersection of y axis

Question 57

where is km on a graph

Answer 57

intersection with x axis

Question 58

where does orthosteric inhibition occur

Answer 58

at the same site (competitive)

Question 59

what varies in competitive inhibition

Answer 59

Km

Question 60

what varies in non competitive inhibition

Answer 60

Vmax

Question 61

how is glucose transported

Answer 61

Na+/glucose symporters | GLUT 1-5 = passive facilitated diffusion transporters

Question 62

what is pyruvate and how many molecules are made during glycolysis

Answer 62

3 carbon molecules x2

Question 63

how many ATP produced in glycolysis

Answer 63

4