Week 6 Metabolism Flashcards
Complete these processes and products
What is the purpose of the krebs cycle? Where does it occur?
Krebs cycle or citric acid cycle is a series of chemical reactions that takes place in mitochondria and is used to release stored energy derived from carbohydrates fats and proteins in the body. It is used by organisms to generate energy for various metabolic processes.
It is cyclical because we begin with citric acid and end with citric acid
What is reduction and oxidation?
Why do we need to reducing power in metabolism?
Reduction is the gaining of electrons.
Oxidation is the losing of elections.
Simplistically anabolic processes often need reducing power (election donors). Hence when we catbolically breakdown products, we are often oxidising and get ATP (energy) and reducing power (NADPH & NADH) to be used for future catabolic processes
What products do we break down in the krebbs cycle?
Acetyl-CoA
Acetyl is produced by thebreakdown of pyruvate, primarily a derivative of carbohydrate (and also aminoacids and fattyacids). When pyruvate breaks down, it produces small bonded carbon molecules (C 2).
When they react with CoA, the combined molecule becomes acetyl-CoA. This is our stored carbohydrate.
What vitamin is need to make CoA?
Vitamin B5 helps make coenzyme A
What are the main products produced from the the Krebbs cycle?
2 x CO2 (waste)
1 x ATP (energy)
3 x NADH (reducing power/ electron transport)
1 x FADH2 (reducing power/ electron transport)
Draw out the krebs cycle (not with every molecule name, more just the general in products and out products along with why each part can be used for)
What is NAD+
NAD+ is a coenzyme that is important for many pathways in the body, including cellular energy, DNA repair, hormone signalling, and inflammation
What is a coenzyme?
A coenzyme is a small organic molecule, often a vitamin or derived from a vitamin, that assists an enzyme in carrying out its catalytic function
What processes does ATP drive?
muscle contraction, nerve impulse propagation, chemical synthesis etc
What is the ATP/ADP equation?
ATP + H2O < —- > ADP + Pi
When glucose is broken down in the pentose-phosphate pathway what do we get form it? What is this used for?
NAHPH is a reducing used in many reactions including cholesterol and fatty-acid synthesis
Which enzymes are produced in which part of the body?
What is the purpose of ghrelin?
Where is it secreted from?
It is secreted by gastric cells
It increases hunger levels.
What supresses ghrelin? What does grehlin inhibit?
Feeding and insulin supress ghrelin
Ghrelin in turn supresses insulin
What is Cholecystekinin? What does it do? Where is it secreted from?
It causes the gallbladder to contract releasing bile.
It also stimulates the secretion of digestive enzymes and slows gastric emptying
Secreted from the duodenum
What is Gastric inhibitory peptide? What does it do?
Where is secreted from?
It inhibits gastric acidification and slow gastric emptying. It encourages the release of insulin.
Secretes duodenum and jejunum
Main fed state hormones
Main empty state hormones
Fed state:
- Insulin
- Cholecystekinin
- Gastric inhibitory peptide
- PYY
Starved state:
- Glucagon
- Grehlin
- Adrenaline
- Cortisol
What is peptide YY? What does it do? WHere is it secreted from?
PYY binds to receptors in the brain to signal feelings of fullness and reduce hunger.
Secreted by ileum & colon
Will out the energy type chart
In glucos metabolism which of these two is anaerobic and which is aerobic?
Anearobic occurs in the cytoplasm and makes lactate (lactic acid). Very ineeficient (good for loosing weight)
Aerobic occurs in the mitochondria, involves the krebs cycle and is much more efficient
What is the purpose of a chylomicron?
Where are they made?
It is a vesticle which enables triglycerides (stored fat) to be transported in the blood (enables them to become contained in a water soluable pokeball)
They are made in the small bowel muscosa
What is it about protein matabolism that breaks down during liver failure?
A biproduct of protein metabolism is ammonia, normally this is detaxified by the liver into urea. However in liver failure this stops being the case and dangerous levels of amonnia build up leading to encepalopathy.
What enzym that breaks down protein is created in the stomach?
Pepsinogen, which with acid becomes pepsin
