4. Systems to Cells Flashcards
(35 cards)
What is the first law of Thermodynamics?
Energy cannot be created or destroyed, only transformed from one form to another.
What do we need energy for?
Cell growth and Division Building new molecules/replacing old ones Movement Breathing Thinking
How is ATP formed?
By substrate-level oxidative phosphorylation
How is energy released from ATP?
By the removal of the end phosphate group by hydrolysis.
What is Hyperglycemia?
High blood glucose.
What is Hypoglycemia?
Low blood glucose.
What does Insulin do?
Stimulates glucose uptake from the blood. Promotes storage of this glucose by turning it to glycogen when there is too much. Lowers blood glucose levels.
What does Glucagon do?
Stimulates glycogen breakdown. Raises blood glucose levels.
What is Gluconeogenesis?
A metabolic pathway that results in the generation of glucose from non carbohydrate substrates such as lactate or amino acids.
What does is mean when enzymes are regulated reciprocally?
When one is active, the other is not.
How does Protein Kinase A regulate glucose metabolism?
Adds a phosphate group to Glycogen synthase b turning it off and to Glycogen phosphorylase a turning it on.
How does Insulin regulate glucose metabolism?
Takes a phosphate group from Glycogen synthase b, turning it on and from Glycogen Phosphorylase a, turning it off.
What benefit comes from membrane compartmentalisation?
Specificity in cells.
How do macro-molecules move between different organelles?
Vesicular Traffic.
How is communication between membrane bound compartments mediated?
By vesicular transport.
Where does insulin fold?
Only in the Endoplasmic Reticulum
What is amplification in insulin signalling?
A single molecule of insulin activates a kinase that can phosphorylate many target molecules.
What is type-1 diabetes?
When your body cannot produce enough insulin to deal with blood glucose levels.
What is type-2 diabetes?
When your body builds a resistance to insulin, making it harder to deal with blood glucose levels.
What pathways can insulin activate?
Glycogen metabolism
Glucose transport
Gene expression
Amplification
What does Endocrine mean?
Endocrine glands secrete hormones (or other products) directly into the blood.
What does Paracrine mean?
A paracrine hormone has effect in the vicinity of the gland secreting it.
What does Autocrine mean?
A cell-produced substances that has an effect on the cell by which it is secreted.
What is the role of Leptin?
To regulated food intake.
