Lectures 6-10

Question 1

What are teratomas?

Answer 1

tumours developing from pluripotent stem cells containing many different cell types

Question 2

What is haemopoiesis?

Answer 2

Blood differentiation

Question 3

What do erythrocytes and platelets stem from?

Answer 3

erythro-megakaryotic progenitors, which come from the common myeloid progenitor

Question 4

What do B and T cells stem from?

Answer 4

Common lymphoid progenitors

Question 5

What are the domains of TF’s?

Answer 5

DNA binding domain
activation domain (interacts with RNA Polymerase)

Question 6

What cycle regulates RBC abundancy?

How does is work?

Answer 6

The erythropoietin cycle
Epo stimulates stem cells in the bone marrow to form RBC progenitors,.
This increases the O2 in carrying capacity, having a negative feedback effect on Epo.
This decreased O2 in the proximal convoluted tubule, increasing Epo production.

Question 7

TCA: what happens to carbon atoms?

Answer 7

They are ‘burned’, being oxidised and released as CO2

The energy released is captured by energy carriers (like NADH), transporting it to oxidative phosphorylation

Question 8

TCA: What kind of molecule is succinate?

Answer 8

symmetriclal

Question 9

TCA: What happens to carbon atoms added by Acetyl CoA?

Answer 9

They are added to oxoaloacetate, and are then lost in subsequent cycles

Question 10

TCA: What are the products of TCA?

Answer 10

CoA + 2CO2
3NADH
FADH2
GTP
REMEMBER THIS HAPPENS TWICE PER GLUCOSE MOLECULE

Question 11

ETC: complexes are there?

Answer 11

4 membrane bound ones, 2 mobile electron carriers

Question 12

ETC: What do NADH and FADH2 do?

Answer 12

transfer high energy electrons to the ECT

Question 13

ETC: what happens to the electrons?

Answer 13

They progressively decrease in energy level, and are added to )2, and then with H+ to form H20

Question 14

ETC: What does the energy released do?

Answer 14

drives protons over the inner membrane into the inter-membrane space

Question 15

ETC: what is the redox potential?

Answer 15

the tendency of an electron donor to reduce an electron acceptor, the more negative the value, the greater the tendency

Question 16

What is the glycerol phosphate shuttle?

Why does it occur?

Answer 16

The regenration of NAD+ from NADH and FADH2 from FAD.
The inner mitochondrial membrane has a low permeability for NADH.
GPS allows the NADH synthesised in the cytosol to contribute to oxidative phosphorylation.

Question 17

What are GLUT’s?

Answer 17

Glucose transporters on the cell surface membrane which allow glucose in by facilitated diffusion

Question 18

What are alleles?

Answer 18

different versions of the same gene

Question 19

What is the nucleosome comprised of?

Answer 19

8 histones, with about 200 base pairs

Question 20

What is the histone code?

Answer 20

a layer of information overlaying the DNA, turning genes on or off

Question 21

What modifies histone tails?

Answer 21

Histone acetyl transferases or histone de-acetylases

Question 22

What happens to a woman’s X chromosomes?

Answer 22

One of them in inactivated (packed into tight chromatin, forming a Barr body)), balancing the differences between males and females

Question 23

What is the difference between substrate level phosphorylation and oxidative phosphorylation?

Answer 23

SL - transfer of phosphate from a substrate to ATP

OX - forms ATP coupled to the oxidation of NADH or FADH(2)

Question 24

What is the regulatory protein for red blood cells?

Answer 24

GATA-1, a transcription factor

Question 25

Where does X inactivation occur?

Answer 25

In the inner cell mass of the blastocyst