Lecture 11 - Respiration Flashcards
(45 cards)
what are the 3 fates of nutrients from the diet?
supply energy, serve as building blocks and stored for future use
how many enzyme controlled steps are in the breakdown of glucose?
19
what is cellular respiration?
a set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients int ATP and then release waste products
what is cell metabolism?
the sum total of all chemical reactions that occur inside the cell
what is catabolism?
the breakdown of larger molecules into smaller ones for the purpose of energy production
what is anabolism?
production of larger molecules to make chemical building blocks for the body
Describe the relationship between ATP in catabolic and anabolic reactions
ATP is used in anabolic and produced in catabolic
what percent of energy from catabolism is used for cellular function?
40%
what is oxidation?
removal of electrons or hydrogen or addition of oxygen which decreases potential energy
after oxidation what are the hydrogen atoms transferred to other compounds by?
coenzymes
what is NAD+?
an oxidising agent
what is NADH?
a reducing agent
what is NAD?
a derivative of the B vitamin niacin
what is FAD?
a derivative of the b vitamin riboflavin
what is the role of an erythrocyte?
to carry oxygen to other tissues, contains no mitochondria or nucleus and is metabolically inactive
Describe the first 5 steps in glycolysis
energy in the form of ATP is invested.
the 6 carbon glucose splits into two 3 carbon of glyceraldehyde 3 phosphate
what is the role of phosphofructokinase ?
its the key regulator of glycolysis, its activity is high when ADP levels are elevated
what occurs when ADP levels are low?
glucose is shunted away from glycolysis to the glycogen storage pathway
Describe the second 5 steps of glycolysis
two glyceraldehyde m molecules are converted into two pyretic acid molecules
ATP is generated, as are NADH + H+
what is the net gain of ATP in glycolysis?
+ 2 ATP
what protein transports pyruvate into the mitochondria?
pyruvate translocase
what occurs during pyruvate decarboxylation?
each pyretic acid is converted into 2-carbon acetyl group which is attached to coenzyme A to form acetyl co enzyme A
what is the net gain from glycolysis and the link reaction (pyruvate decarboxylation)?
2 ATP
4NADH
2 acetyl coenzyme A
Describe the first 4 steps of the Krebs cycle
- entry of acetyl coA to create citrate and regeneration of coA
- isomerisations to isometric acid
- oxidative decarboxylation to remove CO2 and form NADH and alpha ketoglutarate
- oxidative decarboxylation and addition of CoA to form succinylcholine CoA and NADH