Lecture 15 Flashcards
True or false.
Catabolism is the breakdown of material and anabolism is the synthesis of complex organic compounds
True
True or false
Anabolism needs a net energy input whereas catabolism creates a net energy output
true
What is the difference between heterotrophs and autotrophs?
Autographs are able to make material simply from CO2 whereas heterotrophs need to get their energy and metabolites from other organic compounds
What is the general net output of glycolysis?
2 ATP 2 NADH 2H+ 2H20
true or false
glycolysis can continue without oxygen presence
true
true or false
glycerol and amino acids can enter the gluconeogenic pathway at glyceraldehyde-3-phosphate and pyruvate respectively
true
True or false
Gluconeogenesis can aid in the synthesis of glycogen
true
What is a futile cycle?
when cycles are unchecked and ATP will be used up with no progress in either direction of a cycle
What are the main activated carriers in metabolism?
ATP = activated carrier of phosphoryl groups
NADP and NADPH = carrier of electrons
FADH2 = carrier of electrons
Acetyl CoA = carrier of two-carbons molecules
The basic structure of NAD+ is:
A) base-sugar-sugar-phosphate-sugar-base
B) base-sugar-phosphate-phosphate-sugar-base
C) sugar-base-phosphate-phosphate-base-sugar
D) none of the above are the basic structure of NAD+
B
true or false
each electron is associated with an H+ molecule
true
True or false
the vitamin niacin is the derivative of NAD+
true
Based on your knowledge of NAD+, which of the following statements is true?
A) it contains a 3 phosphate group total in its compound
B) Its reduced form contains an additional H on its compound and there is also an extra H+ in solution
c) NAD+ is an inorganic cofactor
D) it is derived from a non-essential amino acid
B
true or false.
NAD+ contains a purine base and its reactive group is the nicotinamide group
true
true or false.
Reduction of NAD+ results in a more acidic solution
true
true or false NAD+ is a reductant and is oxidized
false, reverse
When comparing NAD+/NADH and NADP+/NADPH, which of following statements is NOT true?
A) NAD+/NADH is involved in catabolic reactions
B) NADPH/NADP+ reactions typically work with reducatases whereas NAD+/NADH tend to work with dehydrogenases
C) NADP+ can be transformed to NAD+ by a mitchonchondrial linked transhydrogenase
D) NADPH/NADP+ tend to work in oxidative pathways whereas NAD+/NADH tend to work in reductive pathways
D
true or false
NAD+ kinase can transform NAD+ to NADP+
true
true or false
reductases involve the reduction of substrates whereas dehydrogenases involve the oxidation of substrates
true
What are the change in free energy equations relating enthalpy and entropy as well as concentration?
G= H -TS G= G0' + RTln(CD/AB)
true or false
energy needed to drive biosynthetic reactions is driven by the reduction of organic substrates
false. oxidation of organic substrates is a function of catabolic reactions, which produce energy. Reduction is the role of anabolic reactions and involves net input of energy
Which of the following compounds is NOT able to couple to ATP synthesis? A) PEP B) BPG C) Glucose-6-phosphate D) Creatine phosphate
C
True or false.
The most favorable phosphorylated compound of main donor groups is phosphoenol pyruvate
true
True or false
One would expect creatine phosphate levels to be high when ATP levels are low
false. One would expect creatine levels to be high since this is a product of ATP synthesis
Which of the following are NOT quick regulators of metabolic activity? A) controlling enzyme amount B) substrate level control C) allosteric control D) reversible covalent modifications
A
true or false
glycolysis is a universal process in most living cells
true
What are the two main stages of Glycolysis and their function?
Energy investment and Energy generation
energy investment is to trap and prime the glucose and energy generation is to oxidized products of stage 1 to pyruvate and to harvest ATP
True or false
Glycolysis occurs in the mitochondrial matrix
false. cytosol
What are the 3 fates of pyruvate after glycolysis?
enter TCA cycle, make lactate, or make ethanol under anaerobic fermentation
true or false
Fermentation generates energy but does not change the overall oxidation state of the carbon substrate
true
True or false
Anaerobic respiration occurs in the cytosol
true
True or false
Lactate dehydrogenase is responsible for the regeneration of NAD+
true
True or false
One would expect the the activity of lactate fermentation to increase as pH decreases
true
True or false
lactate and pyruvate are both 3 carbon molecules
True
True or false.
One would expect an increase in pH to increase the rate of NADH product
True
True or false
the delta g of lactate production is -25.1 kj/mol
true
What is the net product of Lactate fermentation per glucose?
2 Lactate 2 ATP and 2 H20
What is hormonal regulation?
- specific cells, target cells
- - respond to hormones if they have a specific receptor protein on their surface
What is an overview of glycolysis?
– 6 carbon sugar is split into 2 3-carbon molecules
– ATP is formed from energy released during this process
– can proceed under aerobic or anaerobic conditions
– regulation is well understood
– universal process in most living cells and plays a central metabolic role by generating energy and intermediates for other pathways
What is the difference between energy investment and energy generation?
- Glucose –> glyceraldehyde 3-phosphate (GAP)
- ——-> trapping and priming
- ——-> attaching phosphate to low energy bond to make something that will release a lot energy later - Oxidation to GAP to pyruvate harvesting ATP
Per glucose how much ATP is consumed, how much is produced and how much NADH is produced?
- 2 ATP consumed and 4 ATP and 2 NADH are produced
- —-> net production 2 ATP and 2 NADH
where does glycolysis take place?
– located in cytosol
What are the three different fates for pyruvate post-Glycolysis?
– Acetaldehyde –> Ethanol (anaerobic alcoholic fermentation)
– Lactate (anaerobic homolactic fermentation)
– Acetyl CoA –> further oxidation (aerobic)
T or F, fermentation generates energy, but no overall change in oxidation state of the carbon substrate
True
T or F, since NAD+ is needed for glycolysis (ATP production) is must be recycled back after glucose is broken down
True; NADH is re-oxidized by reducing pyruvate to lactate
What is the benefit of recycling NAD+ w/ NADH?
– allows glycolysis to continue even in absence of oxygen
T or F, some reactions are so exergonic they’re irreversible
True
What is the fermentation of pyruvate to lactate?
– reaction occurs in microorganisms and in our tissues whenever pyruvate is produced faster than it can be oxidized in the Citric Acid Cycle, conditions of low oxygen availability (e.g. strenuous exercise)
