Biochem block 2 Flashcards

1
Q

What is the difference between catabolism and anabolism?

A

Anabolism is the build up of complex organic molecules from simpler ones, reactions are called anabolic or bio synthetic. They involve dehydration synthesis-release water- and are endergonic
Catabolism. Is the breakdown of complex organic molecules into simpler ones. Reactions are called catabolic or degradative reactions, usually hydrolytic reactions and are exergonic.

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2
Q

Define and distinguish oxidation and reduction.

A

Oxidation: loss of electrons
Gain of oxygen
Loss of hydrogen
The reaction where a substance loses electrons going from a reactant to a product. Reactions where the gain of oxygen is more obvious than the gain of electrons includes combustion-burning- and rusting. The loss of hydrogen can be as oxidation like methyl alcohol- wood alcohol being oxidized to formaldehyde.

Reductions: the gain of electrons
The loss of oxygen
Gain of hydrogen
Reduction often is seen as gain of electrons lie in electroplating silver onto a tea pot, silver is reduced to silver metal by the gain of an electron. The loss of oxygen can be seen in iron ore being reduced to iron metal in a furnace when it reacts to carbon monoxide. Sometimes it can be the gain of hydrogen atoms like carbon monoxide and hydrogen gas being reduced to methyl alcohol.

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3
Q

Summarize the metabolic need for molecular oxygen

A

Molecular oxygen is an essential nutrient as a key substrate for mitochondrial ATP production and a lot of intracellulaire rxns. It’s a common oxidizing agent- electron acceptor, like in aerobic respiration. In Aerobic respiration oxygen is needed to create ATP. One molecule of glucose is converted to 2 molecules of pyruvate to get 2 net molecules of ATP. We also repair our body with ATP, from oxygen

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4
Q

List Metabolic fuel sources

A

Glycogen- muscle carbohydrate stores, blood sugar- glucose, blood fatty acids, triacylglyerols, protein

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5
Q

Besides energy, what else do we need to work efficiently?

A

Enzymes- coenzymes, cofactors: trace minerals and vitamins

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6
Q

What is energy for us?

A

ATP and heat

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7
Q

What are the 4 major biochemical macromolecules?

A

Proteins- amino acid polymers, TAG’s- lipid polymers, DNA,RNA- nucleic acid polymer, Polysaccaride- carbohydrate polymer

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8
Q

What is oxidative phosphorylation?

A

OXPHOS is a process where the oxidation of carbon substrate provides REDUCED COENZYMES. The reduced coenzymes are used to establish a proton gradient. This gradient is coupled to the production of ATP from ADP.

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9
Q

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

A

They are two types of phosphorylation processes that occur. Phosphorylation is the transfer of a phosphate group from one compound to another, usually describing the production of ATP. Substrate level phosphorylation is a direct phosphorylation of ADP with a phosphate group by using the energy obtained from a coupled reaction whereas OXPHOS is the production of ATP from the oxidized NADH and FADH.

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10
Q

What is substrate level phosphorylation?

A

It’s an enzymatically coupled reaction that produces ATP by the transfer of a phosphate group from a reactive intermediate generated during catabolism to ADP. An example is glycolysis- the catabolism of glucose to pyruvate. Pyruvate go through TCA cycle which breakdown the carbon intermediates to 6 CO2, 6H20 and 38 ATP for one glucose molecule

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11
Q

Are B vitamins water soluable?

A

Yes

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12
Q

What is B1?

A

Thiamine. Alcoholics are deficient

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13
Q

What is B2?

A

Riboflavin

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14
Q

What is B3?

A

Niacin

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15
Q

What is B9?

A

Folate

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16
Q

What is B5?

A

Pantothenic acid

17
Q

What is B6?

A

Pyridoxine

18
Q

What is B7?

A

Biotin

19
Q

What is B12?

A

Cobalamin

20
Q

Where to deficiencies manifest themselves?

A

In rapidly growing tissues. Skin, tongue, GI tract, fragile tissue in the corner of lips ( cheilitis)

21
Q

How to Niacin/B3 deficiencies present?

A

Often in corn based diets. Pellagra. Dermatitis, Diarrhea, Dementia, and Death.

22
Q

Vitamin B3/Niacin can be what in contrast to the other B vitamins?

A

Can be produced from tryptophan in a vitamin B6-dependent reaction.

23
Q

What is required to synthesize vitamin B3/niacin?

A
  1. NAD+ (oxidation, glycolysis, TCA)

2. NADPH (fatty acid synthesis, oxidative phosphorylation)

24
Q

What is Kwashiorkor?

A

Inadequate nutrition, adequate total calories, deficient in protein. Edema in extremities, distended belly from lack of albumin production.

25
Q

What is Marasmus?

A

Inadequate calories with respect to protein and carbohydrates. Overall muscle wasting.

26
Q

Where do the central metabolic pathways occur?

A

ETC, and oxidative phosphorylation take place in the mitochondrial membrane.
Glycolysis, pentose phosphate pathway and FA biosynthesis happen in the cytosol of the cell.

27
Q

Describe the essential role of Folate- B9?

A

Absorption: Duodenum and jejunum- adversely effected by EtOH
Requirements: no true store- maybe weeks to months
Deficiency markers: hypersegmented neutrophils, elevated homocysteine
Deficiency symptoms: megaloblastic anemia, neural tube defects in pregnancy
DNA synthesis: select forms directly required for dTMP and all purines

28
Q

Describe the essential role of Colbalamin- B12?

A

Absorption: terminal ileum (requires R-binders and IF)
Requirements: Liver stores (4-6 years)
Deficiency markers: Hypersegmented neutrophils elevated homocysteine, *ELEVATED METHYL MALONIC ACID
Low serum B12
Deficiency symptoms: megaloblastic anemia *PERIPHERAL NEUROPATHY
DNA synthesis: indirectly required due to methyl trap

29
Q

Describe the essential role of Pantothenic acid- B5?

A

Required for beta-oxidation, TCA, Acetyl-CoA formation

Deficiencies are rare due to an abundance in a variety of food sources

30
Q

Describe the essential role of Thiamin- B1?

A

Largely in decarboxylation rxns.
Cofactors for: pyruvate dehydrogenase- glycolysis to TCA, alpha-ketogluterate hydrogenase- TCA cycle, alpha-ketoacid dehydrogenase- BCAA and transketolase-PPP