PPT-Richard

Question 1

2 types of metabolism

Answer 1

Catabolism and anabolism

Question 2

What is a futile cycle?

Answer 2

When two biochemical reactions run simultaneously, expending a lot of energy

Question 3

What are the two types of control?

Answer 3

Internal and external

Question 4

What is internal control?

Answer 4

Participants on the pathway itself accept how it progresses

Question 5

What is external control?

Answer 5

Factors form elsewhere affect the pathways progress

Question 6

What is negative feedback?

Answer 6

Inhibition of a process by presence of large amounts of final product (sending the message that the process has produced enough product

Question 7

What is precursor/reactant activation?

Answer 7

Activation of a process by the presence of large amounts of initial reactant (sending the message that the process hasn’t consumed enough reactant)

Question 8

Types of mechanisms

Answer 8

Indirect allosteric mechanisms
Direct mechanisms

Question 9

What is allosteric control?

Answer 9

Regulator molecule binds to the enzyme at a different site that the one to which the substrate binds to altering enzyme conformation

Question 10

Common form of allosteric control?

Answer 10

ATP & AMP

Question 11

What is direct inhibition?

Answer 11

Inhibitor competes with substrate for the active site

Question 12

What is the michaelis-menton equation?

Answer 12

V = Vmax.([S]/[S] + [Km])

Question 13

What is the lineweaver-Burke plots?

Answer 13

Vmax and Km: 1/V=Km/Vmax.1/[S] + 1/Vmax
AKA
y=mx+c

Question 14

What is concept of affinity?

Answer 14

The higher the affinity, the less ligand is needed to induce 50% maximal binding

Question 15

What are signals?

Answer 15

Hormones and nerve impulses

Question 16

What are the hormones that act as signals?

Answer 16

Amino acid-derived hormones
Steroid hormones

Question 17

Properties of amino acid-derived hormones

Answer 17

Can’t cross plasma membrane
Initiate intracellular responses
Change response in gene expression, protein activity and membrane permeability

Question 18

Properties of steroid hormones

Answer 18

Hydrophobic (can cross plasma membrane)
Ligands for cytoplasmic receptors
Changes gene expression

Question 19

Types of non-steroids hormone receptors

Answer 19

Extracellular regions
Cytosolic regions

Question 20

What are extracellular regions?

Answer 20

Interact with hormones
Series of repeated stretches of hydrophobic amino acids

Question 21

What are cytosolic regions?

Answer 21

Interact with transducers
Initiate intracellular responses to signals

Question 22

What are the 3 functional domains in steroid hormone receptors?

Answer 22

Binding hormone
DNA binding
Receptor to activate the promoters of gene being controlled

Question 23

What is saturation binding?

Answer 23

As hormone concentration rises, concentration of hormone bound to receptor rises until no more can bind

Question 24

What is scatchard plot?

Answer 24

Mathematical manipulation allows saturation binding to be expresses as straight line

Question 25

What is an autocrine?

Answer 25

A cell produces a signal that binds to receptors on its own surface, affecting its own activity

Question 26

What is a paracrine?

Answer 26

Signalling molecules are released by a cell and affect nearby target cells

Question 27

What is an endocrine?

Answer 27

Chemical signals are secreted into the blood and carried to the cells they act upon

Question 28

Definition of signal transduction

Answer 28

A basic process in molecular cell biology involving the conversion of a signal from outside the cell to a functional change within the cell

Question 29

What are the 5 major classes of steroid hormones?

Answer 29

Mineralocorticoids (increase blood volume & pressure) Glucocorticoids (promote high blood glucose) Androgens (development of male sexual characteristics) Estrogens (development of female sexual characteristics) Protestagens (maintenance of pregnancy)

Question 30

Where do the receptor proteins sit?

Answer 30

In the cytoplasm

Question 31

What is the zinc finger domain?

Answer 31

Essential for gene expression Proteins that bind to specific DNA sequences to control the transcription of genetic information 4 cysteine bind zinc to stabilise the structure

Question 32

How many zinc fingers does a receptor dimer have?

Answer 32

2- stabilises the structure and allows specificity of binding

Question 33

What do the receptor dimers bind to?

Answer 33

2 half sites within the DNA sequence

Question 34

What are the two types of specific response elements?

Answer 34

Palindromic-TGTTCT…TCTTGT Direct repeats-TGACCT…TGACCT

Question 35

What forms the RNA polymerase catalysing site?

Answer 35

Two binding sites for the DNA (promoter and enhancer) Causes a loop

Question 36

What causes electrical or nervous signalling?

Answer 36

Movement of ions across the membranes

Question 37

What do gated channels do?

Answer 37

Can bring about changes in the ionic environment in the cell, and cause a cellular response

Question 38

What are the consequences of changes in membrane permeability?

Answer 38

Changes in pH or oxidation state Supplying proteins with ionic co-factors Supplying cells with energy Changes in potential difference across membrane

Question 39

What are the different forms of Ca2+ as a signal?

Answer 39

Buffered form-bound to soluble or membrane linked Ca2+ buffers Mineral form- collagen rich matrix onto which crystals of insoluble calcium phosphate are laid

Question 40

What is conformational change?

Answer 40

Ca2+ presence with cells rigger changes in enzymatic activity/ protein movement

Question 41

What are regulated discrete localised releases of Ca2+?

Answer 41

Signal’s which trigger a range of cellular responses

Question 42

Where does Ca2+ signalling occur?

Answer 42

In all eukaryotic cells

Question 43

Flow diagram of Ca2+ system

Answer 43

-Stimulation of cell: Entry of calcium into localised parts of cell and binding of calcium to biological molecules -Cellular response: Expulsion of calcium from cell -Cell recovery

Question 44

Why does the ER have a larger surface area than the plasma membrane?

Answer 44

To mop/pump up Ca2+ that has leaked into the cytoplasm and act as a Ca2+ store

Question 45

How many Ca2+ mobilisation systems do cells have?

Answer 45

2 parallel systems

Question 46

How is Ca2+ released into the cytoplasm?

Answer 46

Channels in the plasma and ER membrane

Question 47

How is Ca2+ removed from the cytoplasm?

Answer 47

PMCA pump in PM and SERCA pump in ER membrane

Question 48

What is catabolism?

Answer 48

Stimulation of glycogen breakdown signalled by glucagon and adrenaline

Question 49

What is anabolism?

Answer 49

Stimulation of glycogen synthesis signalled by insulin

Question 50

What does hyperglycaemia lead to?

Answer 50

Excess glycation of proteins and lipids

Question 51

What is dyslipidaemia?

Answer 51

Inability of body to deal with excess fat

Question 52

What are two cardiovascular complications of type 2 diabetes?

Answer 52

Atherosclerosis-inflammation associated accumulation of fatty/glycated deposit is on interior surface of coronary arteries Coronary heart disease-blood trapped in the occluded artery closes, causing a coronary thrombosis

Question 53

What are PPARs?

Answer 53

Ligand activated transcription factor receptor proteins that alter genes in order to act as insulin sensitising agents, lower blood glucose and boost anti inflammatory defence