Proteins

Question 1

What are Nucleotides made up of?

Answer 1

Sugar
Nitrogenous bases - Purines(A-G), pyrimidines T/U, C, nitrogen
Phosphoryl group

Question 2

What joins nucleotides?

Answer 2

Phosphodiester bonds between adjacent carbons of the sugar.

Question 3

What do base pairs join by?

Answer 3

Hydrogen bonds

Question 4

Process of DNA Replication?

Answer 4

1. Separation of strands as hydrogen bonds are broken (by DNA Helicase) unzipping the DNA
2. A small strip of RNA (Primer) kick starts replication by adding complementary nucleotides
3. DNA Polymerase then adds complementary base pairs and phosphodiester bonds form leaving a new strand

Question 5

Types of Mutation?

Answer 5

Insertion - Base inserted changing code
Deletion - Base deleted

Question 6

Types of RNA?Function?

Answer 6

Messenger RNA (mRNA) - Decodes DNA
Ribosomal RNA (rRNA) - Decodes mRNA
Transfer RNA (tRNA) - Facilitates protein formation

Question 7

Describe Transcription ?

Answer 7

DNA > mRNA
1) DNA unwinds
2) RNA Polymerase replicates template
3) Promoter region - DNA region next to which initiates Transcription by controlling RNA Polymerase
4) Enhancers - DNA regions that attract transcription factor proteins (control rate of transcription)

Question 8

How does exercise regulate gene expression?

Answer 8

Gene expression is governed by signals sent to the cell after exercise, therefore the number of cells will modulate the number of mRNA copies.
Signals produced from different types of exercise will affect which region of the gene is copied meaning different mRNA/proteins will be produced.

Question 9

Describe mRNA splicing?

Answer 9

After Transcription, the introns from the code are spliced leaving only exons, which leaves the nucleus to begin translation.

Question 10

Describe translation?

Answer 10

Formation of a protein from mRNA

MRNA binds to the rRNA where it is decoded and translation begins.

tRNA molecule binds the anticodon to the codon releasing an amino acid which joins via peptide bonds.

Process repeats until stop codon is reached, protein is released

Question 11

What is the primary structure of proteins ? What does this determine?

Answer 11

Amino acid chain linked by carboxyl and amino group (also contains a side chain)

Shape and function of protein

Question 12

Describe Secondary structure?

Answer 12

Alpha helix and beta pleated sheet, dependent on folds and twists

Question 13

Describe Tertiary structure ?

Answer 13

Entire polypeptide chain with different folds due too hydrogen bonds, disulphide bonds, electrostatic bonds.

Question 14

Describe quaternary structure ?

Answer 14

Multiple polypeptide chains

Question 15

What are enzymes? function (how)?

Answer 15

Essential biological catalyst, which accelerate metabolic reactions.
By binding to the complementary substrate it causes a quicker formation of transition state which is required for the reaction, by doing this it lowers activation energy.

Question 16

Factors affecting enzyme reaction?

Answer 16

Substrate availability
Enzyme concentration
Temperature and pH

Question 17

What is the most common protein detection method?

Answer 17

The Western Blot

Question 18

The Western Blot protocol?

Answer 18

Collect sample
Homogenize to extract protein
Electrophoresis to separate sizes
Electrotransfer protein from gel to membrane
Antibody probing and detection

Question 19

How many Amino acids make up a protein and how many are essential?

Answer 19

20
9 essential

Question 20

Digestion of proteins in the stomach?

Answer 20

Stomach secretes gastrin hormone, which stimulates the release of hydrochloric acid and pepsinogen (converts to pepsin) via gastric glands which breakdown proteins due to low pH and catalysing of hydrolysis of peptide bonds

Question 21

Processing of protein in the small intestine?

Answer 21

It passes from the stomach to the duodenum where the acidic conditions causes the release of bicarbonate, which causes the release of secretin, allowing further bicarbonate into the intestinal lumen.

Question 22

Protein content of the Human body?

Answer 22

Men = 16%
Women = 14%

Question 23

Protein turnover in the body?

Answer 23

Constant state of synthesis and breakdown, if synthesis is higher = muscle gain, if lower = muscle loss

Question 24

Effects of Resistance exercise (RE) on protein turnover?

Answer 24

Sufficient protein intake with RE = hypertrophy

Question 25

Effects of Endurance exercise on protein turnover?

Answer 25

Not really linked to hypertrophy, Increases mitochondrial content Mitochondrial biogenesis Mitochondrial hypertrophy allowing more ATP

Question 26

What is Amino acid degradation and the two types?

Answer 26

Removal of the a-amino acid group Deamination Transamination

Question 27

What is Deamination?

Answer 27

Serine, Theronine and glutamine lose a-amino group, forming a-keto acids and ammonium. Ammonia is converted by the liver into urea and excreted

Question 28

What is Transamination?

Answer 28

Transfer one amino group to another, catalysed by aminotransferase, the most common keto-acid is alpha ketoregulate

Question 29

What can a-keto acids be converted too? (5)

Answer 29

Pyruvate Acetyl CoA Succinyl CoA Oxaloacetate Fumurate

Question 30

How is ammonium build up prevented ? (2)

Answer 30

Glutamine synthetase catalyses conversion of glutamate to glutamine using ATP Alanine is produced when pyruvate receives amino group of glutamine, catalysed by alanine aminotransferase forming a-ketoregulate

Question 31

Effects of exercise on Amino acid (AA) metabolism?

Answer 31

AA's are used for glucose synthesis via gluconeogenesis , and due to high glucagon/low insulin gluconeogenesis is active.

Question 32

Urea Cycle? (five parts)

Answer 32

Amino acids are broken down into Ammonia during deamination This then links to Ornithine to produce Citruline Citruline is then converted to arginosuccinate This splits to arginine and fumarate Arginine is hydrolysed via arginase to form urea

Question 33

Recommended daily protein intake?

Answer 33

0.8g per kgof body weight 1.2-1.4 for endurance 1.2-1.7 for resistance training

Question 34

What is protein quality assessed by?

Answer 34

Amino acid composition – in particular leucine and BCAA’s. Digestibility of amino acids – easier digestion, quicker absorption

Question 35

Difference between DNA and RNA

Answer 35

DNA = double helix, RNA = Single strand DNA has histones Bases - DNA has T, RNA has U Sugars - DNA = Deoxyribose, RNA = Ribose

Question 36

How do amino acids join?

Answer 36

Covalently via peptide bonds

Question 37

Different types of proteins?(6)

Answer 37

Enzymes Structural eg collagen, keratin, actin and myosin Transport eg haemoglobin, ion channels Hormones Antibodies Receptors

Question 38

Process of Glucose Alanine cycle?

Answer 38

Pyruvate is formed from glycolysis and used for further production of ATP through OP or anaerobic conditions however in the presence of excess amino acids it can be transaminated to form alanine in muscle cells. An amino group is transferred to pyruvate forming alanine and a-ketoglutarate. Alanine is released into the blood and transported to the liver where transamination occurs again, forming pyruvate and glutamate Pyruvate undergoes gluconeogenesis forming glucose 6 phosphate which is dephosphorylated to glucose and released into the blood to be used

Question 39

Which enzyme breaks down pyruvate to lactate?

Answer 39

Lactate dehydrogenase

Question 40

What best describes type 1 muscle fibres?

Answer 40

Lower excitation threshold, high resistance to fatigue, metabolically oxidative