Week 2 Flashcards
Define metabolic pathways?
Biochemical reactions that occur in progression from the substrate to product, usually involving enzymes and cofactors
What is the difference between anabolic and catabolic pathways?
anabolic: builds molecules, use energy
catabolic: breaks down molecules, produce energy
What are the three steps of catabolism?
- digestion: break down of complex molecules to their component building blocks
- conversion of building blocks to acetyl CoA (or other simple intermediates)
- metabolism of acetyl CoA to Co2 and formation of ATP
What is an oxidation-reduction reaction?
The movement of electrons
Oxidised organic compounds
– Increased oxidation state or loss of electrons
Reduced organic compounds
– Decreased oxidation state or gain of electrons
How do enzymes control oxidation/reduction reactions
dehydrogenases remove hydrogen ions from energy-containing nutrients and donate them to oxygen to form water (and ATP is produced)
What do Niacin and riboflavin do?
help transport hydrogens from energy-yielding compounds to oxygen in metabolic pathways
What is the difference between anaerobic and aerobic respiration?
Anaerobic:
- no oxygen
- respiration of one glucose molecule= 2 ATP
Aerobic
- oxygen
- respiration of one glucose molecule= 32 ATP
What are the 4 steps of aerobic metabolism of glucose?
- Glycolysis (anaerobic step): Glucose is oxidized to pyruvate
- Pyruvate is metabolized to acetyl coenzyme A (CoA) by pyruvate dehydrogenase.
- Acetyl CoA enters citric acid cycle (CAC) producing NADH+ H+, FADH2, and CO2
- Electron Transport Chain: oxidative phosphorylation. ATP is derived from NADH + H+ and FADH2 as H+ travel down the concentration gradient from the intermembrane space via ATP synthase.
What is lipolysis?
Triglycerides broken down into free fatty acids and
glycerol
What is Beta-oxidation?
fatty acid oxidation
1 fatty acid made of 16 carbons makes how many ATPs?
106
how are fatty acid molecules turned into acetyl molecules?
beta-oxidation
Carbohydrates aid in fat metabolism to some extent. true or false?
true
What are the 5 stages of formation of ketone bodies?
- blood insulin drops
- lipolysis promoted and FA’s stores in adipose tissues are released
- FA’s taken up by the liver
- liver oxidized the FA’s to acetyl-CoA then to ATP
- when there is enough ATP, the liver cells combine 2 acetyl-CoA molecules together to form a 4 carbon molecule. this is further metabolized into ketone bodies
Define Ketogenesis
formation of ketones
define ketosis
elevated levels of ketones in the blood
Define ketoacidosis
high levels of ketones making the blood more acidic
Where are ketone bodies formed?
in the liver from the break down of fatty acids
Define deamination
removal of the amine group from the carbon skeleton
what is gluconeogenesis
forming new glucose from glucogenic amino acids
- from non-glucose sources)
Which is the first organ to receive the most nutrients from GIT via portal vein?
Liver
What happens when there is a high level of ATP?
Anabolic reactions are activated
What happens when there is a high ADP or AMP to ATP ratio
Catabolic reactions are activated
What does the post prandial (fed) state promote?
Up-regulation of relevant enzymes of:
- Glucose synthesis glycogenesis
- Fat synthesis (lipogenesis)
- Protein synthesis
- Urea synthesis
What is the primary hormones that is involved in the post prandial state?
Insulin
Does the post prandial state promote catabolism or anabolism
Anabolism
What does the fasting state promote?
Hepatic glycogen breakdown glycogen turning to energy for muscles Protein breakdown fat breakdown ketogenesis
Where does the conversion of glucose to glycogen occur
Liver
Describe what happens due to uncontrolled diabetes mellitus type 1?
- Insufficient insulin production due to damage pancreas
- glucose cannot get into the cells which rely on insulin for glucose transport
- large amounts of FA’s released from adipose cells
- FA’s flood the liver and are broken down into acetyl CoA - slows CAC
- High production of ketone bodies
- ketoacidosis??
What is Glycolysis? Where does it occur
Glucose to pyruvate
Cytosol
What is the transition reaction? Where does it occur?
Pyruvate to acetyl CoA
Mitochondria
What is fatty acid oxidization? Where does it occur?
Fatty acids to acetyl CoA
Mitochondria
What is glycogenic amino acid oxidation? Where does it occur?
Amino acid to acetyl CoA
cytosol
What is non-glucogenic amino acid oxidation
amino acid to acetyl CoA
Mitochondria
what happens in the Citric Acid Cycle? where does it occur?
acetyl CoA to Co2
mitochondria
