Making Heme

Question 1

What kind of side chain groups are added on to the pyrrole ring structure?

Answer 1

methyl
acetate
propionate
vinyl chemical groups

Question 2

which of the porphyrins do no coordinate a metal ion?

Answer 2

the phycobilins found in red algae and in cyanobacteria

Question 3

which of the porphyins coordinate Mg ions?

Answer 3

the Cholrophylls

Question 4

which of the porphrins coordinate Fe?

Answer 4

Heme which is in, hemoglobin, myoglobin, CP450,

Question 5

which of the porphyrins coorddinate Co?

Answer 5

the Cobalamins like Vitamin B12

Question 6

Where are the Nitrogens in Heme taken from?

Answer 6

Gylcine

Question 7

how many red blood cells are degraded per hour?

Answer 7

100/200 Million Red blood Cells

Question 8

What is the only mammalian tissue that does not make heme?

Answer 8

the Mature Red Blood cells

Question 9

where does the most Heme synthesis happen?

Answer 9

in the erythroid tissue this tissue is made up of cells in the bone marrow that are red blood cell producing also there is a lot of heme synthesis happening in the liver

Question 10

why is there different regulation of Heme synthesis between the liver and the bone marrow?

Answer 10

all of the heme being made in the bone is for making hemoglobin whereas in the the liver the Heme is for other things like Cytochrome P450

Question 11

How is Fe stored and transported in the body?

Answer 11

1: the Fe travel in the blood through binding to apotransferrin after being absorbed by the duodenum around 1-2mg per day
2: The Fe Transferrin complex is engulfed in receptor mediated endocytosis
3: the Fe is separated and stored as ferritin in the bone marrow
4: The receptor and the apotransferrin are then recycled back to the cell membrane to be used again

Question 12

which reactions in the Heme synthesis pathway happen in the Mt?

Answer 12

the first reaction and the last three reactions

Question 13

what is the first reaction in the Heme synthesis pathway dependant on?

Answer 13

Vitamin B6

Question 14

what does it mean if something has the suffix ogen?

Answer 14

these are reduced precursor forms of Heme

Question 15

Is anaemia a main symptom of porphyria?

Answer 15

No. Heme is still synthesised in adequate quantities

Question 16

Which drugs increase the demand for Heme?

Answer 16

barbiturates
sulfur drugs 
antifungals/hypertensives
retroviral drugs 
vasodilators 
oral contraceptives

Question 17

in what three ways does Heme affect the production of ALAS1?

Answer 17

it affects the promotor for ALAS one
leading
to impaired transcription, destabilises the mRNA and the protein of ALAS 1
reduced translocation to the mt from the cytosol
and direct inhbition of ALAS 1
fasting also activated a transcrptional co activator of ALAS1 increasing the amount of ALAS1

Question 18

how is ALAS 2 controlled?

Answer 18

by coordinating Heme synthesis with globin synthesis

Question 19

what other enzymes are condtroleld in erythroid tissue?

Answer 19

uroporphyrinogen cosynthase

and ferrochelatase

Question 20

what else may influence Heme synthesis?

Answer 20

drugs and the circadian clock