Chapter 7 - Hemoglobin

Question 1

How many times as much Energy is extracted from glucose in the presence of oxygen?

Answer 1

15 times

Question 2

What two types deliveries does vertebretes does in the circulatory system of O2 transport/storage?

Answer 2

Hemoglobin & Myoglobin

Question 3

Where do you find Hemoglobin at?

Answer 3

Found in Red Blood Cells & carries O2 from lungs to tissues, also carries CO2/H+ back to lungs

Question 4

True or False: Myoglobin carries O2 supply as a reserve

Answer 4

True

Question 5

True or False: Hemoglobin & Myoglobin are nearly identical in structures.

Answer 5

True

Question 6

How many lobes or subunits does hemoglobin have?

Answer 6

4 Subunits that can bind O2 cooperatively

Question 7

How many percent of capacity does Hemoglobin have on O2?

Answer 7

About 90% of potential O2, more efficient than myoglobin

Question 8

For both Hemoglobin and Myglobin, 3d structure is affected in what way and what will it cause?

Answer 8

A single amino acid substitution can cause disease ie. sickle cell anemia.

Question 9

What is it called when O2 is free in Myoglobin?

Answer 9

deoxymyoglobin

Question 10

What is it called when O2 is bound in Myoglobin?

Answer 10

oxymyoglobin

Question 11

What makes O2 binding possible ?

Answer 11

Prostethic HEME group makes it possible for O2 binding.

Question 12

How many percent of capacity does Myoglobin have on O2?

Answer 12

7% of O2 capacity

Question 13

What is HEME?

Answer 13

• Heme gives blood the color red
• An organic compound w/ central iron atom
• Bound iron can be Fe2+ or Fe3+ but only Fe2+ will bind iron.

Question 14

How many additional bonds can the Fe form?

Answer 14

2, top and bottom

Question 15

Heme-bond Iron can be both

Answer 15

Fe2+ and Fe3+ but O2 can only bind to Fe2+

Question 16

In Myoglobin, what does it do to the O2 complex?

Answer 16

Myoglobin stabilizes the O2 complex so that the superoxide cannot leave.

Question 17

What is the hemoglobin compose of regarding its structure?

Answer 17

It consist of 2 Alpha chains and 2 Beta chains with each chain consisting of heme group.

Question 18

True or False: Hemoglobin forms alpha beta dimers. alpha1 Beta1 & alpha2 beta2

Answer 18

True

Question 19

What is the curve for Myoglobin vs. Hemoglobin?

Answer 19

Myoglobin curve is on the left of hemoglobin

Question 20

True or False: At high concentrations, not a lot of O2 is bound.

Answer 20

False

Question 21

What type of binding does the hemoglobin perform?

Answer 21

Coperative Binding

Question 22

What is Cooperative binding?

Answer 22

Binding of O2 at one site increases the likelihood that O2 will bind to another hemegroup

Question 23

Where does O2’s path?

Answer 23

O2 goes from high concentration in the lungs to low concentration in the tissues.

Question 24

What is the influence of coop binding

Answer 24

Even at high O2 concentrations without coop we would get O2 to bind to hemoglobin very well.

Question 25

What is the effect of O2 binding to Heme group?

Answer 25

When O2 binds,there is 15 degree rotation and so the dimers are more able to move around when O2 is bound.

Question 26

What are the two states of Hemoglobin?

Answer 26

DeoxyHemoglobin which is Tense state (T) and OxyHemoglobin which is in Relaxed state (R)

Question 27

Altering the structure at the heme group does what?

Answer 27

A histidine binding causes a shift and structural changes at Fe in 1 subunit is directly transferred to other subunits.

Question 28

Is T-state stable or unstable?

Answer 28

It is unstable which means that it is unfavorable to release O2 which is bad for us.

Question 29

What is the purpose of 2,3-BPG?

Answer 29

2,3-BPG helps release O2. Without BPG, only 8% of O2 would be released.

Question 30

How does BPG work?

Answer 30

It binds in the center of the tetramer and in T to R state, BPG release and lowers O2 affinity. BPG also relaxes T-state

Question 31

Where does CO bind?

Answer 31

CO2 binds to heme at the same site O2 does.

Question 32

True or False: CO binds the same tight as O2.

Answer 32

False, CO binds 200 times more tightly to heme, even at low pressure.

Question 33

Which state does CO cause the Heme?

Answer 33

CO causes heme to go to R-state

Question 34

With the relase of O2 what compounds help with releasing?

Answer 34

H+ and CO2. High concentration of CO2 and low pH will increase O2 release.

Question 35

Where does CO2 bind?

Answer 35

CO2 binds allosterically than O2.

Question 36

What is the bohr effect on O2 affinity?

Answer 36

O2 affinity decreases as pH decreases and O2 is released.

Question 37

How does CO2 induces O2 release?

Answer 37

1st CO2 reacts with H2O and produces carbonic acid which in turn creates bicarbonate ion and makes H+ and pH low. 2nd is CO2 stabilized dexoyhemoglobin (T-state) by reacting with terminal amino groups to form carbamates.

Question 38

What is the result of altering amino acid sequence in heme?

Answer 38

a disease caused by amino acid sequence my result in mutation.

Question 39

how is the mutation caused in Sickcle Cell Anemia?

Answer 39

Valine is replaced with glutamic acid.