MCAT Quicksheets Biochem

Question 1

At a low pH are amino acids protonated or deprotonated

Answer 1

Protonated

Question 2

At a high pH are amino acids protonated or deprotonated

Answer 2

Deprotonated

Question 3

What is it called when an amino acid has a neutral pH

Answer 3

Zwitterion

Question 4

What type of reaction is a peptide bond formation

Answer 4

Condensation/dehydration

Question 5

How are peptide bonds broken

Answer 5

Hydrolysis

Question 6

Describe the primary structure of a protein

Answer 6

Linear sequence of amino acids

Question 7

Describe secondary structure of proteins

Answer 7

Local structure
Stabilized by hydrogen bonding
Alpha Helices
Beta pleated sheets

Question 8

Describe tertiary structure of proteins

Answer 8

3D structure stabilized by hydrophobic interactions, acid base interactions (salt brides), hydrogen bonding, and disulfide bonds

Question 9

Describe quaternary structure of proteins

Answer 9

Interaction between subunits

Heat and solutes can cause denaturation

Question 10

What are ligases responsible for

Answer 10

Joining 2 large biomolecules, often same type

Question 11

What are isomerases responsible for

Answer 11

Catalyze interconversion of isomers

Question 12

What are lyases responsible for

Answer 12

Catalyze cleavage without addition of water or transfer of electrons

Question 13

What are hydrolases responsible for

Answer 13

Catalyze cleave with addition of water

Question 14

What are oxidoreductases responsible for

Answer 14

Catalyze oxidation reduction reactions that involve transfer of electrons

Question 15

What are transferases responsible for

Answer 15

Move a functional group from one molecule to another

Question 16

Describe saturation kinetics

Answer 16

As substrate concentration increases, reaction rate also increases until max value is reached

Question 17

Describe a competitive enzyme

Answer 17

Binding site: Active site
Km: increases
Vmax: no change

Question 18

Describe Noncompetitive enzyme

Answer 18

Binding site: Allosteric site
Km: No change
Vmax: Decreases

Question 19

Describe mixed enzyme

Answer 19

Binding Site: Allosteric Site
Km: Increases or decreases
Vmax: Decreases

Question 20

Describe uncompetitive enzyme

Answer 20

Binding site: Allosteric Site
Km: Decreases
Vmax: Decreases

Question 21

What is a nucleoside

Answer 21

Contain 5 carbon sugar bound to a nitrogenous base

Question 22

What is a nucleotide

Answer 22

Nucleosides with 1-3 phosphates groups added

Question 23

What is cellulose

Answer 23

Main structural component of plant cell walls

Main source fiber in human diet

Question 24

What are starches

Answer 24

Amylose, Amylopectin

Main energy storage forms for plants

Question 25

What is glycogen

Answer 25

Major energy storage form for animals

Question 26

What is agarose gel electrophoresis used for

Answer 26

Separating DNA molecules by size

Question 27

What is southern blotting used for

Answer 27

Detecting presence and quantity of various DNA strands in a sample

Question 28

Where does translation occur

Answer 28

At ribosome

Question 29

What is a silent mutation

Answer 29

No effect on protein synthesis

Question 30

What is a nonsense (truncation) mutation

Answer 30

Produces a premature stop codon

Question 31

What is a missense mutation

Answer 31

Produce a codon that codes for a different amino acid

Question 32

What are frameshift mutations

Answer 32

Result from nucleotide addition or deletion | and charge the reading frame of subsequent codons

Question 33

What is the initiation codon

Answer 33

AUG

Question 34

What are the termination codons (3)

Answer 34

UAA AGA UAG

Question 35

What are the 3 types of RNA

Answer 35

Messenger Transfer Ribosomal

Question 36

What is the role of mRNA

Answer 36

Carries message from DNA in nucleus via transcription of gene

Question 37

What is the role of tRNA

Answer 37

Brings in amino acids

Question 38

What is the role of rRNA

Answer 38

Makes up much of ribosome | enzymatically active

Question 39

What are the important enzymes of glycolysis

Answer 39

``` Glucokinase Hexokinase Phosphofructokinase 1 (PFK) PFK-2 Glyceraldehyde-3phosphate dehydrogenase 3-phosphoglycerate Kinase Pyruvate kinase ```

Question 40

What is the role of glucokinase

Answer 40

Part of glucose sensor and responsive to insulin in liver

Question 41

What is the role of hexokinase

Answer 41

Traps glucose

Question 42

What is the role of PFK 1

Answer 42

Rate limiting step

Question 43

What is the role of PFK 2

Answer 43

Produces F2,6-BP which activates PFK 1

Question 44

What is the role of Glyceraldehyde-3phosphate dehydrogenase

Answer 44

Produces NADH

Question 45

What is the role of 3-phosphoglycerate Kinase

Answer 45

Performs substrate level phosphorylation

Question 46

What is the role of pyruvate kinase

Answer 46

Substrate level phosphorylation

Question 47

What are the steps that catalyze irreversible reactions of glycolysis

Answer 47

Glucokinase Hexokinase PFK1 Pyruvate kinase

Question 48

What is pyruvate dehydogenase

Answer 48

Converts pyruvate to acetyl-CoA

Question 49

What are the components of the Citric Acid Cycle

Answer 49

``` Pyruvate Acetyl CoA Citrate Isocitrate Alpha Ketoglutarate Succinyl CoA Succinate Fumarate Malate Oxaloacetate ```

Question 50

What is the mnemonic for the Citric Acid Cycle

Answer 50

``` Cindy Is Kinky So She Fucks More Often ```

Question 51

How many NADH, FADH, GTP or ATP are produced from the citric acid cycle

Answer 51

NADH: 3 FADH: 1 GTP: 1

Question 52

How many NADH, FADH, ATP, or GTP are produced in glycolysis

Answer 52

NADH: 2 ATP: 2

Question 53

How many NADH, FADH, ATP, or GTP are produced in pyruvate dehydrogenase

Answer 53

NADH: 1

Question 54

Where does gluconeogenesis occur

Answer 54

Cytoplasm and mitochondria | Primarily in liver

Question 55

What is the role of the liver

Answer 55

Maintains blood glucose | Processes lipids, cholesterol, bile, urea, and toxins

Question 56

What is the role of adipose tissue

Answer 56

Stores and releases lipids

Question 57

What is the role of a resting muscle

Answer 57

Conserve carbohydrates as glycogen and uses free fatty acids for fuel

Question 58

What is the role of a cardiac muscle

Answer 58

Uses fatty acid oxidation