Module 6 Objectives Flashcards
What are the laws of thermodymamics?
- Energy cannot be created or destroyed
- Conversion of one form of energy into another always leads to a loss of energy, typically, in the form of heat
- A highly organized system contains a lot of potential energy while a system that is disorganized (high chaos = entropy) contains a low amount of potential energy)
What is metabolism?
The sum of all biochemical reactionsin a cell or organism.
metabolism = catabolism + anabolism
What is catabolism?
The sum of all degradative reactionsin a cell or organism.
Generate energy (ATP, heat) and oxidize carbon (electrons to NAD+, NADP+, and FAD);
Large —> small
What is anabolism?
The sum of all biosynthetic reactionsin a cell or organism.
Require energy (ATP) and reduce carbon (electrons from NADH, NADPH and FADH2)
Small —> large
What is the formula for Photosynthesis (Phototrophs)?
6 CO2 + 6 H2O + Sunlight —–> C6H12O6
What is the formula for Cellular Respiration (Heterotrophs)?
C6H12O6 —-> 6 CO2 + 6 H2O + ATP
What are the steps of macronutrients to ATP?
Catabolism of proteins, fats, and carbohydrates in the three stages of cellular respiration.
Stage 1: oxidation of fatty acids, glucose, and some amino acids yields acetyl-CoA.
Stage 2: oxidation of acetyl groups in the citric acid cycle includes four steps in which electrons are abstracted. S
tage 3: electrons carried by NADH and FADH2 are funneled into a chain of mitochondrial (or, in bacteria, plasma membrane–bound) electron carriers — the respiratory chain — ultimately reducing O2 to H2O. This electron flow drives the production of ATP.
What is glucose catabolism?
- The ‘splitting’ of ‘sugar’
- Partial oxidation of C (—> NADH)
- ATP (small amount)
- Primary source of metabolic energy in some mammalian tissues and cell types (brain, red blood cells, anaerobic muscle, sperm,…)
- Two-phase process
- Many enzymes of glycolysis are Mg2+-dependent
10 enzymatic steps (make 2 NADH and 2 ATP
Glucose (C6) —-> 2 pyruvate (C3)
What is kinase?
Catalyze transfer of a phosphate group from one organic molecule to another, usually involving ADP or ATP (most of these are non-reversible)
What is Phosphatase?
Remove a phosphate group, yielding inorganic phosphate (Pi)
What is Isomerase?
Catalyze the formation of an isomer of the substrate (requires the breaking of a bond, reversible reactions)
What is Dehydrogenase?
Catalyze redox reactions (coenzyme NAD+/NADH, FAD/FADH2 or NADP+/NADPH)
What is the TCA cycle?
8 intermediates (metabolites)
8 enzymes
- 4 Dehydrogenases(2 catalyze an oxidative decarboxylation)
Location: Matrix of mitochondria
Yield per acetyl-CoA:
- 2 CO2 (waste)
- 3 NADH
- 1 FADH2
- 1 ATP
What is oxidative phosphorylation?
What is fatty acid catabolism?
What is amino acid catabolism?
What is fermentation? How does it work?
What are the micronutrient requirements for bioenergentics?
What are the structure and function of enzymes?
Stucture:
Enzymes are proteins
Enzymes have an active site that is complementary to the substrate.
Functions:
Enzymes = Biocatalysts
- Increase reaction rate (v0) by lowering the activation energy of a chemical reaction
What are examples of alcohol dehydrogenase?
The big picture of alcohol (ethanol) processing in our body (primarily in the liver)
ADH ALDH CH3CH2OH ----> CH3CHO ----> CH3COO-
Acetaldehyde Acetate
What is acetaldehyde to the body? What is it quickly converted into?
It is toxic and a known carcinogen; does normally not accumulate as it is quickly converted to acetate.
What is acetate used for?
Energy production (TCA cycle and oxidative phosphorylation)
As a building block for fatty acids, stored in the form if triglycerol (fat)
What are enzyme kinetics examples?
Explain Michaelis-Menten inhibitors.
- Normal binding
- Competitive inhibition
- Mixed inhibition
- Uncompetitive inhibition
- Normal binding: normal substrate in the active site
- Competitive inhibition: different substrate in the active site blocking the normal substrate
- Mixed inhibition: different substrate in a different active site; normal substrate can’t bind because changes the original active site shape
- Uncompetitive inhibition: different substrates on different active site; normal substrate can still bind
What is the schematic depiction of inhibitor action?
Competitive: Vmax - unchanged; Km - increases
Mixed: Vmax - decrease; Km - increases (allosteric effect)
Uncompetitive: Vmax - decrease; Km - decreases
Explain enzyme regulation beyond the MM-model.
Intracellular can be covalent or non-covalent, but are both reversible
Extracellular are covalent, but non-reversible
What are physiological examples of enzyme regulation?
Blood clotting - Beneficial
Blood clotting - pathologies
- Myocardial infarction (heart attack)
- Cerebrovascular Accident (stroke)
- DVT = Deep Vain Thrombosis
- Pulmonary Embolism
