Metabolism L1.2 Flashcards
State the role of homeostasis
Counteracts imbalances to internal environment
It is a dynamic equilibrium.
Can exist al all levels
1. Cells (regulation of intracellular Ca2+ conc)
2. Tissue (balance between cell proliferation + apoptosis / cell death)
3. Organs (kidne regulates water + ion conc of blood)
4. Organism (maintenance of body temp)
Describe body fluid homeostasis
Balance between fluid gain and fluid loss
(must be maintained at optimum level)
Describe uses of blood
- Transport
-supplies oxygen
-supplies nutrients for utilisation, storage, interconversion
-removal of waste products, CO2, urea, lactic acid
-sginalling (e.g. hormones) - Coagulation
- Immune functions
- Regulation of body pH
- Regulation of core body temp
- Hydraulic functions
State the normal fasting plasma conc of glucose (mmol/L)
5
Describe chemical bond energies in chemical reactions
Breaking chemical bonds = releasing energy
Making chemical bonds = uses energy
Describe exergonic reactions
More energy released than used
Describe endergonic reactions
More energy used than released
Define Gibbs free energy (G)
Energy released in exergonic reaction, available to do work.
Exergonic reactions occur spontanously + provide energy to drive endergonic reactions
Explain Gibbs free energy CHANGE
Measured in kj/mol or kcal/mol
If free energy change is -ve: net loss of energy, reaction occurs spontaneously
If free energy change is +ve: reaction needs input of free energy so must be coupled with exergonic reaction
Homeostasis and Energy Questions
Describe the role of H-carrier molecules
Carriers of reducing power for ATP production
State examples of major carrier molecules
Flavin
Nicotinamide
Which vitamin provides flavin?
B2
Which vitamin provides nicotinamide
B3
Give the oxidised and reduced form of flavin
Oxidised: FAD
Reduced” FADH2
Give the oxidised and reduced form of nicotinamide
Oxidised: NAD+
Reduced: NADH + H+
Why is the total concentration of “oxidised and reduced” carriers constant?
Reduced carriers quickly re-xodised
Diagram showing overview of catabolism
Breifly describe the four stages of catabolism
- DIET MACRONUTRIENTS: macronutrients from diet converted to cellular fuel
- Cellular fuel to metabolic intermediates (releases energy + some reducing power)
- TCA cycle / citric acid cycle / krebs cycle (releases energy + some reducing power)
- Oxidative phosphorylation (reducing power converted to ATP)
Which pathways are activated by high energy signals?
Anabolic pathways
(high conc ATP)
Which pathways are activated by low energy signals?
catabolic pathways
low conc atp
Describe ATP synthesis under anaerobic conditions during exersice
During exercise,
CREATINE PHOSPHATE generates ATP for use by exercising muscle
Describe ATP synthesis under anaerobic conditions during rest
ATP accumulates and is used to make creatine phosphate
Describe ATP synthesis in aerobic conditions
ATP produced via oxidative phosphorylation
Describe different energy stores
Muscle (creatine phosphate) - short term store (few seconds)
Carbohydrates - immediate use - short term (min/hours)
Fat stores (adipose tissue) long term (40 days)
Muscle protein (obtain energy under extreme conditions)
