Biochem Halo-halo

Question 1

Remarks on porphyrins

Answer 1

Porphyrins form complexes with metal ions that bind to the nitrogen atom of each of the four pyrrole rings

Question 2

Examples of porphyrins

Answer 2

IRON PORPHYRINS
Heme
MAGNESIUM PORPHYRIN
Chlorophyll

Question 3

Where are heme found

Answer 3

Hemoglobin
Myoglobin
Cytochrome C
Cytochrome P450
Catalase
Tryptophan pyrrolase
Nitric oxide synthase (NOS = heme +FMN/FAD)

Question 4

Turnover of hemoglobin

Answer 4

~6grams of hemoglobin daily

*human adults normally destroy about 200 billion RBCs per day

Question 5

Catabolism of heme

Answer 5

Carried out in the microsomal fraction of cells by heme oxygenase

Question 6

Remarks on bilirubin

Answer 6

Since 1 g of hemoglobin yields about 35 mg of bilirubin, human adults form 250-350 mg of bilirubin per day.

Question 7

Remarks on vitamin B6

Answer 7

Neurological damage: >100-200mg/day

Sensory neuropathy: 2-7g per day

Question 8

Remarks on ATP

Answer 8

~65 kg of ATP recycled per day (Sciencedirect)

Question 9

Organ with the highest ATP use per gram

Answer 9

Kidney?

24g atp per g of tissue

Question 10

Estimated daily use of ATP

Answer 10

(g ATP/ g Tissue)
Kidneys: 24
Skeletal muscle running: 23.6
Skeletal muscle rest: 0.3
Heart: 16
Brain: 6
Liver 6

Question 11

Organ with highest lactate production

Answer 11

RBC (29g/day)

Question 12

Function of polyphenol

Answer 12

1. Act as water-soluble radical trapping antioxidants
2. Inhibits neurotoxic effects of beta-amyloid protein in alzheimers
3. Iron choletor - neuroprotective in PD, AD, huntington dse (HD)
4. Arrest cellular growth in tumors
5. Reduced plt activity, BP
6. Slows starch digestion, protects beta cells from glucose toxicity
7. Inhibits lipogenesis, increases energy expenditure

Question 13

Cancers with evidence of beneficial effects from polyphenols

Answer 13

Colon
Prostate
Epithelial
Endometrial
Breast

Question 14

Health effects of ammonia

Answer 14

Eye irritation to blindness

Question 15

Define linkage specificity

Answer 15

Linkage specificity means that enzymes break one type of bond

Question 16

4 types of specificity of enzymes

Answer 16

Absolute
Group
Linkage
Sterochemical

Question 17

Absolute specificity

Answer 17

Absolute specificity means that one and only one substrate will fit with a particular enzyme. The enzyme glutamate dehydrogase will catalyze only the removal of the nitrogen group from glutamate- NOT any other amino acid. It has absolute specificity.

Question 18

Group specificity

Answer 18

Group specificity means that an enzyme will catalyze a reaction on a function group of a variety of molecules (for instance, cleaving an alcohol group or working only on aldohexose sugars)

Question 19

Stereochemical specificity

Answer 19

Stereochemical specificity means that enzymes will only work on one enantiomer. For example they could break D-sugars but not L-sugars. This enzyme is D-Lactate Dehydogenase complexed with D-lactic acid

Question 20

Most common vitamin deficiency

Answer 20

Vitamin A

Question 21

Most common micronutrient deficiency

Answer 21

Iron, affecting more than 30% of world’s population (~2 billion people) (Bailey et al, 2015; WHO 2005)

15% of worldwide population(Bishop 2018; 2007)