PSL300 Lecture 6 Flashcards
What are the 2 states metabolism can have?
- fed, absorptive, anabolic
2. fasted, postabsorptive, catabolic
What is metabolism?
sum of all chemical reactions in the body
Define: anabolic
use glucose for energy
Define: catabolic
???
What is BMR?
Basal metabolic rate.
Amount of energy an individual uses when resting at a comfortable temperature, not eating. (Amount of energy to exist comfortably)
What is energy balance?
Caloric intake and output (exercise)
Define: gluconeogenesis
make glucose from non-carbohydrate sources (e.g. glycerol, amino acid)
What processes does glucose undergo to get broken down in order to be used as energy?
- Glycolysis
- TCA & oxidative phosphorylation
Final product = ATP
What processes does fatty acids and glycerol undergo to get broken down in order to be used as energy?
Bata oxidation of FFA
final product: ATP
How is glucose stored?
- what does it get stored as?
- what processes store it?
- what process converts it back?
- where is it stored?
- stored as glycogen
- glucose -> glycogen = glycogenesis
- glycogen -> glucose = glycogenolysis
- stored in liver, muscles
How is fatty acids and glycerol stored?
- what does it get stored as?
- what processes store it?
- what process converts it back?
- stored as triglycerides
- fatty acid -> triglyceride = lipogenesis
- triglyceride -> fatty acid = lipolysis
- stored in adipose tissue
How are amino acids stored?
- what does it get stored as?
- what processes store it?
- what process converts it back?
- stored as protein
- amino acid -> protein = protein synthesis
- protein -> amino acid = protein degradation
- stored in muscle
What are the 3 basic nutrients?
glucose
fatty acids/glycerol
amino acids
The 3 essential nutrients are stored as ______ units, but when needed for energy, are ________ units.
bigger
smaller
1 hour after a person has eaten, which of the following would you expect to observe?
a) gluconeogenesis in the liver
b) lipolysis in fat cells
c) protein synthesis in muscle cells
d) glycogenolysis in the liver
EXPLAIN AND DEFINE TERMS.
c
gluconeogenesis = production of glucose from non-carbohydrates (glucose from meal, so no need to make more)
lipolysis = break down of triglyceride to fatty acids (no need for energy)
protein synthesis = amino acids turn to protein (for storage of access amino acids, so yes!)
glycogenolysis = break down of glycogen to glucose (no need for more glucose)
What hormones are produced by the endocrine pancreas?
insulin
c peptide
glucagon
somatostatin
Enzymes secreted by the pancreas go into….
Duodenum
Hormones secreted by the Islet of Langerhans go into…
the blood stream
What is found in the pancreas that contains cells that secrete hormones?
Islet of langerhans
what is the Islet of Langerhans surrounded by?
Exocrine/acinar cell
what is another word for acinar cell?
exocrine cell
what can be found on exocrine cells?
zymogen
What are zymogen?
???
What can be found in abundance in the Islet of Langerhans, and what is their function?
capillaries to transport hormones into the blood stream
What are 3 cells that can be found in the Islet of Langerhans?
- Beta cell
- alpha cell
- delta cell
What does the beta cell secrete?
Mostly insulin
Some c-peptide
What does the alpha cell secrete?
glucagon
what does the delta cell secrete?
somatostatin
what is insulin still inside the beta cell called?
proinsulin
What signals target cells to change between the fasting/feeding states?
Insulin + glucagon signals
what type of receptor does insulin bind to?
receptor-enzyme
what type of receptor does glucagon bind to?
G protein-coupled receptor
what is the basic cascade of effects that binding of insulin or glucagon causes on a cell?
binding to receptor -> second messenger system -> phosphorylate proteins -> cellular response
what doe the graph of glucose concentration to time look like?
morning: 80 increases after every meal but completely recovers (except breakfast) after breakfast: 100 each meal causes increase to be bigger. falls back to around 80 at night
what doe the graph of insulin concentration to time look like?
slightly lags behind [glucose] graph
- morning: 15
- peaks after meals
- peaks most in morning then decreases
- mostly recovers after each peak, but usually a bit lower
- night: 10
what doe the graph of glucagon concentration to time look like?
- mostly steady
- inverse to [glucose]: glucose high = lower glucagon
- around 1~2 constantly
what controls glucose homeostasis?
insulin to glucagon ratio
