2- integration of metabolism

Question 1

what is glycolysis?

Answer 1

breakdown of glucose (6C) to 2 pyruvate (3C)
also has NAD+ to NADH

Question 2

what is TCA cycle? (pretty much just lists some molecules involved)

Answer 2

• starts with pyruvate, all C-C bonds cleaves & then complete oxidation of C atoms to CO2
• NAD+ to NADH and FAD+ to FADH
• pyruvate & acetyl coA important

Question 3

what is gluconeogenesis?

Answer 3

reverse of glycolysis (makes glucose from non COH precursors and provides glucose for brain)

Question 4

what is fatty acid oxidation/ketogenesis?

Answer 4

• start with triglycerides in adipose tissue
• lipolysis splits fatty acids from glycerol
• FA then undergo oxidation
• intermediates in fatty acid breakdown include ketone bodies (ketones are strongly acidic and have sickly sweet smell)

Question 5

what is glycogenolysis?

Answer 5

• start with glycogen containing n glucose residues
• finish with glycogen containing n-1 glucose residues and liberated glucose

→rely on this for any form of physical activity (break down glycogen to get glucose when exercise)

Question 6

what is a muscle enzyme?

Answer 6

creatine kinase - high CK suggests muscle damage

Question 7

what are inborn errors of metabolism?

Answer 7

set of diseases where enzymes involved in pathways are inefficient (example is glycogen storage disease). most of them present in first few years of life, often present acutely. a lot of them do well once treated

Question 8

what are symptoms of glycogen storage disease?

Answer 8

if glycogen can only be added to and not broken down then store will just keep building up meaning massive enlargement of liver & hypoglycaemia & cardiorespiratory failure

Question 9

what happens if don’t have insulin?

Answer 9

means lots of pathways aren’t switched on and some pathways are switched off - results in diabetic ketoacidosis which is medical emergency, hyperglycaemia in blood and can spill into urine

Question 10

what is important history for diabetic ketoacidosis?

Answer 10

history of feeling thirsty and peeing all the time leading to dehydration (because hyperglycaemia in blood spilling into urine meaning peeing out loads of glucose to get rid of it)

Question 11

what happens with insulin resistance?

Answer 11

1. when tissues become resistance to insulin they can’t take up glucose effectively, in response to this, body shifts to alternative fuel sources
2. lipolysis is breakdown of fat into free fatty acids & glycerol - the free fatty acids are taken up by liver
3. the fatty acids in liver produce triglycerides and packaged into VLDL and leads to elevated levels of LDL (bad cholesterol) in blood

Question 12

how does cancer mess with metabolism?

Answer 12

• tumour cells need to generate lots of energy and provide building blocks of cells so they scavenge pathways and steal metabolites etc
• they also outgrow their blood supply forcing them to live in low oxygen&nutrient environment and to respond to this they make more energy from metabolism and use it for themselves

Question 13

what is tumour lysis syndrome?

Answer 13

potentially life-threatening condition that occurs when a large number of tumor cells die rapidly, releasing their intracellular contents into the bloodstream

→often caused by treatment of cancer like chemotherapy

Question 14

does gut flora influence body metabolism?

Answer 14

yes