IMMS: Cells & metabolic processes Flashcards
Metabolic fuels & diet; Glycolysis, Krebs & oxidative phosphorylation; Fatty acid oxidation & ketones; Living control mechanisms; Membrane ultrastructure & transport; Water & sodium
What is metabolism?
Life-sustaining chemical reactions taking place within each cell.
What is a xenobiotic?
A substance that has never come from a living thing e.g. chemicals that have been completely synthesised. Needs to be broken down in the body and excreted.
What is an anabolic process?
A process where larger molecules are synthesised from smaller components. Used in constructive metabolism e.g. storage of fats.
What is a catabolic process?
A process where larger molecules are broken down into smaller components. Used in oxidative and waste disposal processes.
What is the difference between daily energy expenditure (DEE) and basal metabolic rate?
DEE = total number of calories burned in 24h period, including for physical activity.
Basal metabolic rate = number of calories per hour needed to stay alive at complete rest, not including digestion or physical activity.
How much protein is needed in the diet per day?
0.8g/kg/day.
What is the most energy dense: protein, lipids, or carbohydrates?
Lipids (9kcal/g)
Protein & carbohydrates are only 4kcal/g
How much does 10ml of alcohol weigh?
How many units of alcohol is this?
8mg (less dense than water).
One unit of alcohol.
What is the average basal metabolic rate?
1kcal/kg/hour average (but depends on a variety of factors).
Name 7 factors that affect basal metabolic rate (BMR).
F A B M I S T
Food intake
Age
BMI
Muscle mass
Infection/disease
Sex
Thyroid function
How many kcal/g is alcohol?
7kcal/g
What are the 9 essential amino acids?
Happy Iguana Left Lisbon, Making a Pilgrimage To TransylVania.
Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine
What is another name for Vitamin A?
Retinol.
Name the 8 B vitamins.
The Right Number Potentially Passes By Four Cunts
B1: Thiamin
B2: Riboflavin
B3: Niacin
B5: Pantothenic acid
B6: Pyridoxine
B7: Biotin
B9: Folate
B12: Cobalamin
Can B vitamins be stored in the body?
Most B vitamins cannot be stored. Folate and B12 can be stored in the liver.
What happens if you take too much pyridoxine?
Too much pyridoxine (B6) can cause peripheral neuropathy.
What do cobalamin, folate, and iron have in common?
They are needed for making red blood cells. Deficiencies can cause B12/folate/iron deficiency anaemias.
Which vitamin is needed to prevent scurvy?
Ascorbic acid/vitamin C.
What is the main function of calciferol (Vitamin D)?
Regulating the amount of calcium and phosphate in the body.
Which vitamin is tocopherol?
Vitamin E.
Which vitamin, stored in the liver, is vital for clotting and wound healing?
Vitamin K
What mineral is needed in diet for making thyroid hormones?
Iodine
Which vitamins are fat soluble?
A, D, E, K
Which vitamins are water soluble?
Vitamin C and most of the B vitamins.
What percentage of daily energy should come from free sugars?
No more than 5%
What is the maximum amount of saturated fat for women and men?
20g for women. 30g for men.
What is the recommended maximum amount of salt per day?
6g of salt
What are the guidelines around alcohol intake?
No more than 14 units of alcohol per week, spread over at least 3 days, with some alcohol free days.
What are the substrates and intermediates of the Krebs Cycle?
Citrate Is Krebs Starting Substrate For Making Oxaloacetate
Acetyl CoA -> Citrate -> Isocitrate -> alpha Ketoglutarate -> Succinyl-coA -> Succinate -> Fumarate -> Malate -> Oxaloacetate
Where does the Krebs Cycle occur and in what conditions?
Mitochondrial matrix under aerobic conditions.
What provides the final common pathway for oxidation of carbohydrates, fats, and proteins?
The Krebs Cycle.
Where does oxidative phosphorylation occur and in what conditions?
Inner mitochondrial membrane under aerobic conditions.
Which generates more energy, Krebs Cycle or oxidative phosphorylation?
Oxidative phosphorylation, around 30 ish ATP per glucose molecule.
What are the two key components of oxidative phosphorylation?
The Electron Transport Chain (ETC) and chemiosmosis.
How is H2O produced in respiration?
The final electron acceptor in ETC is oxygen, which picks up the final electrons and hydrogen = H2O.
What are the five components of Adenosine 5’ Triphosphate (ATP)?
Adenine base + ribose + three phosphate groups which are linked with high energy bonds.
How does hydrolysis of ATP into ADP release energy?
Breaking bond between phosphate groups releases energy.
What is glycolysis?
Metabolic pathway which converts glucose into 2x pyruvate, with a net gain of 2x ATP.
Where does glycolysis occur and in what conditions?
In cytoplasm, can occur in anaerobic or aerobic conditions.
What is the primary method of ATP generation for erythrocytes and why?
Glycolysis, because erythrocytes lack mitochondria (Krebs and oxidative phosphorylation occur in mitochondria).