GS - Metabolic pathways Flashcards
Which of the following best defines metabolism?
a) Balancing energy intake to maintain body weight
b) Homeostasis of blood glucose levels
c) The breakdown of food to release energy
d) The sum of anabolic and catabolic reactions within cells
d) The sum of anabolic and catabolic reactions within cells
The primary function of cellular respiration is to generate ATP. Which of the following summarises this process?
a) Anabolism of glucose
b) Glycogenolysis
c) Oxidation of glucose
d) Reduction of glucose
c) Oxidation of glucose
Proteins, carbohydrates and fats can all be metabolised to generate a common precursor which then enters the mitochondrial matrix and citric acid cycle. What is this molecule?
a) Acetyl CoA
b) Citric acid
c) Lactic acid
d) Pyruvic acid
d) Pyruvic acid
During exercise when oxygen is not readily available, NADH + H+ unloads its hydrogen atoms back onto pyruvic acid yielding which product?
a) Acetyl
b). Acetyl CoA
c). Lactic acid
d). Malic acid
c). Lactic acid
The answer to the previous question is an example of what type of reaction?
a). Anabolism
b). Catabolism
c). Oxidation
d). Reduction
d). Reduction
At which stage of cellular respiration is CO2 generated?
a) Citric acid cycle
b) Electron transport chain
c) Glycogenesis
d) Glycolysis
a) Citric acid cycle
Which of the following most accurately describes the citric acid cycle?
a) A process which enables both catabolism and anabolism of important metabolites
b) A process which results in only the anabolism of substances
c) A process which results in only the catabolism of molecules
d) A process which takes place in anaerobic conditions
a) A process which enables both catabolism and anabolism of important metabolites
The electron transport chain takes place on the inner mitochondrial membrane. Direct utilisation of which molecule is exclusive to this stage of cellular respiration?
a) Carbon dioxide
b) NADH + H+
c) Oxygen
d) Water
c) Oxygen
Which mechanism generates the energy for creating an electrochemical gradient between the mitochondrial matrix and inner membrane?
a) Oxidation and reduction of cytochrome complexes
b) Oxidation of NADH + H+ and FADH2
c) Phosphorylation of ADP to ATP
d) Reduction of oxygen to water
a) Oxidation and reduction of cytochrome complexes
Approximately, what is the net gain of ATP from the complete metabolism of two glucose molecules, under aerobic conditions?
a) 4
b) 30
c) 60
d) 80
d) 60
The formation of glucose from non-carbohydrate sources such as glycerol and amino acids in the liver, is known as?
a) Gluconeogenesis
b) Glycogenesis
c) Glycogenolysis
d) Glycolysis
a) Gluconeogenesis
Which component of the citric acid cycle is generated by beta oxidation of fatty acids?
a) Acetic acid
b) Acetyl CoA
c) Pyruvic acid
d) Succinyl CoA
b) Acetyl CoA
A person has been on a hunger strike for seven days. Compared to normal, which of the following is most likely?
a) Elevated glucose concentration in the blood
b) Increased glycogen synthase activity in the liver
c) Increased plasma insulin concentrations
d) Increased release of fatty acids from adipose tissue and ketosis
d) Increased release of fatty acids from adipose tissue and ketosis
Transamination of amino acids results in the formation of which molecules?
a) Essential amino acids
b) Keto acids
c) Ketone bodies
d) Non-essential amino acids
b) Keto acids
In the absorptive state, anabolism exceeds catabolism. What is the fate of excess metabolites, regardless of source at this stage?
a) Continued cellular respiration
b) Conversion to glucose and storage as glycogen
c) Degradation in the liver and excretion in urine
d) Transformation into triglycerides
b) Conversion to glucose and storage as glycogen
