Homeostasis, Nutrition, Digestion Flashcards
What happens 1st when you stop eating?
- Breakdown glycogen
- about 6 hours after feeding – after turn to fatty acids
Phase 2 after not eating
- Ketosis, fat-burning
- Ketone bodies replace energy fuel
- Athletes may be in it more often
- Brain cannot directly use these, too thick to fit through the BBB
- Brain drains last of glucose
- Recalibrates requirement starts eating ketone bodies
Phase 3 - not eating
Protein burning, rapid muscle depletion
- The body starts eating itself – catabolises
- Mostly, cardiac arrest kills you – tissue degradation
A loss of more than ____% of water can be deadly
12%
How is the shape of enzymes determined?
Hydrogen bonding
Role of Kidneys
Filter blood
remove waste and excess solutes
Urea
Byproduct of protein metabolism
Ammonia
Toxic
How do kidneys work?
- Enter through renal artery
- Branch to specialized capillaries (glomerulus)
- Arterial pressure forces water/solutes out of capillaries
- Into tubule/collecting duct
Nutrients processed by kidney
Glucose, sodium, chloride
Wastes process by kidneys
Urea, creatinine
How do we regulate heat?
a) Conduction
b) Radiation
c) Evaporation
Example: Conduction
Lizard pressed against warm rock
Example: Radiation
Light coloured butterfly gains less heat then dark one
Example: Evaporation
sweating, panting
Endotherms
Maintain a high body temp in cold environments
Ectotherms
depend on environmental heat to maintain their body temperature
Osmosis
Water moving down conc. gradient
High to low
Passive
Why do we require iodine?
To make hormones
Why do we require carbs?
Energy, carbon
Why do we require lipids?
Concentrated energy
Required to make certain compounds
e.g. linoleic acid required to make prostaglandins and cell membranes
Why do we need proteins?
Source of amino acids
We cannot synthesize some amino acids naturally
Peristalsis
Muscle driven movement of the gut
Small Intestine
Epithelial cells absorb nutrients (active transport) and secrete enzymes
Pancreas
Source of digestive enzymes
lipase, proteases, amylase
