Block 2 Lecture 7 & 8: Protein folding + Chemical Energy

Question 1

To change from primary to secondary structure, which bonds must be formed between amino acid side chains?

Answer 1

Hydrogen bonds

Question 2

what are the two kinds of secondary strucutre

Answer 2

alpha helix and beta pleated sheet

Question 3

Tertiary structure involves the collapse of ______ components and the facing outwards of ______ components

Answer 3

the collapse of hydrophobic components and the facing outwards of hydrophilic components

Question 4

what are the bonds present in tertiary structure between non-polar amino acid side chains, and how strong are they relatively

Answer 4

Van der Waals, weak

Question 5

what bonds are present between polar side chains in a tertiary structure

Answer 5

hydrogen bonds

Question 6

what bonds are there between charged amino acid side chains on a tertiary structure, and how strong are they relatively?

Answer 6

ionic bonds, weak

Question 7

What structure of protein do disulphide bridges form and between what two molecules do they form?

Answer 7

form in a tertiary structure between two cysteine molecules. Is a strong bond

Question 8

what does a quaternary structure consist of?

Answer 8

two or more polypeptide chains each with their own tertiary structure

Question 9

homodimer and heterodimer complexes are part of which classification of protein structure?

Answer 9

quaternary

Question 10

where are membrane anchored and secretory proteins initially translated?

Answer 10

on cytoplasmic ribosomes

Question 11

What is the name of the particle that recognises the signal peptide when it emerges from the ribosome after being translated?

Answer 11

the SRP, signal recognition particle

Question 12

what is the function of the SRP, the signal recognition particle?

Answer 12

targets specific receptors in the ER membrane

Question 13

is the signal sequence found at the C terminus or the N terminus of the polypeptide chain?

Answer 13

the N terminus

Question 14

what is the process for the translocation of a secretory protein (e.g a hormone) across the ER membrane?

Answer 14

chain is completely translocated and the signal sequence is cleaved off by a signal peptidase.

Question 15

Do secretory proteins remain insoluble in the ER lumen once they have been translocated?

Answer 15

No, they are effectively solubilised in the lumen once they have been translocated.

Question 16

What is the process for the transaction of a membrane protein across the ER membrane?

Answer 16

one or more of the hydrophobic segments of the polypeptide chain anchors it in the bilayer

Question 17

Which of membrane and secretory proteins are moved via transport vesicles from the ER to the Golgi?

Answer 17

Both membrane and transport proteins are moves via transport vesicles from the lumen of the ER to the Golgi

Question 18

What are the different types of vesicles that operate from the Golgi?

Answer 18

Transport vesicles which move proteins to lysosomes, Membrane vesicles which merge proteins to the membrane of the cell, secretory vesicles which export proteins out of the cell via exocytosis.

Question 19

Which face of the Golgi are vesicles packaged at?

Answer 19

The trans face of the Golgi

Question 20

______ reactions transfer energy from complex molecules to ATP

Answer 20

catabolic

Question 21

______ reactions transfer energy from ATP to complex molecules

Answer 21

anabolic

Question 22

do catabolic or anabolic reactions result in the storage of energy

Answer 22

catabolic

Question 23

what facilitate the transfer of glucose from the bloodstream into a cell?

Answer 23

insulin

Question 24

what facilities the conversion of stored glucose, as glycogen, to glucose in the bloodstream?

Answer 24

glucagon

Question 25

Is glycolysis anaerobic or aerobic and where does it occur?

Answer 25

anaerobic, occurs in the cytoplasm

Question 26

what is the reactant and what is the product of glyoclysis

Answer 26

Glucose turns into two molecules of pyruvic acid and four ATP

Question 27

How many ATP are used in the process of glycolysis

Answer 27

2 ATP

Question 28

How many NAD molecules are reduced by glycolysis

Answer 28

2

Question 29

what must happen in between glycolysis and the Krebs cycle?

Answer 29

the formation of Acetyl CoA

Question 30

How is Pyruvic acid converted to Acetyl CoA

Answer 30

aerobic process in the mitochondrial matrix

Question 31

is the formation of Acetyl CoA anaerobic or aerobic

Answer 31

aerobic, requires O2

Question 32

What does the Krebs Cycle produce from 1 molecule of Acetyl CoA

Answer 32

1 x ATP, 2 x CO2, 1 x FADH2 and 3 x NADH

Question 33

Where does the Krebs Cycle occur and is it an aerobic or anaerobic process?

Answer 33

in the mitochondrial matrix, is aerobic

Question 34

During the electron transport chain, what does the enzyme ATP synthase do as protons move back across the mitochondrial membrane?

Answer 34

Phosphorylate ADP to ATP

Question 35

what is the final electron acceptor in the electron transfer chain

Answer 35

O2, forms water

Question 36

ETC uses energy from _____ reactions to fuel pumping of protons up a concentration gradient from matrix to inner membrane space

Answer 36

redox

Question 37

what is proton motive force derived from

Answer 37

the energy rich electrochemical gradient

Question 38

how many protein complexes form the ETC?

Answer 38

4

Question 39

what two kinds of phosphorylation are present during cellular respiration?

Answer 39

substrate level phosphorylation (Krebs and Glycolysis) and oxidative phosphorylation (ETC)

Question 40

Does NAD+ or FAD promote the production of more ATP

Answer 40

NAD

Question 41

where is insulin produced

Answer 41

by beta cells of Islets of Langerhans in pancreas

Question 42

what is the function of insulin

Answer 42

promote glucose uptake into cells (for ATP production or storage in liver). insulin produced when blood sugar levels are high

Question 43

where is glucagon produced

Answer 43

Produced by alpha cells of Islets of Langerhans in pancreas

Question 44

what is the function of glucagon

Answer 44

Stimulates the breakdown of glycogen to increase blood sugar levels

Question 45

Diabetes Mellitus : a disease in which the body’s ability to produce or respond to the hormone____ is impaired, resulting in abnormal metabolism of carbohydrates and _____ levels of glucose in the blood.

Answer 45

insulin, results in elevated/increased levels of glucose in blood

Question 46

what is the difference between type 1 and type 2 diabetes

Answer 46

type 1: beta cells of pancreas are destroyed so insulin is not produced. type 2: body produces insulin but receptors are non-functional

Question 47

what is the most common form of diabetes

Answer 47

type 2

Question 48

what are some side effects of diabetes

Answer 48

excessive thirst, frequent urination, weight loss, fatigue