Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
|
A. Absorptive (fed or postprandial) state:
What is the major process? |
Anabolic processes exceed catabolic processes
|
|
|
A. Absorptive (fed or postprandial) state:
1. CHO's |
Converted to Glucose
Converted &stored as glycogen in the liver & then cells |
|
|
A. Absorptive (fed or postprandial) state:
2. Lipid |
transported in the lymph
Before entering cells they are hydrolysed to fatty acids and glycerol before passing through capillary walls Liver, muscle and adipose tissue use lipid as their primary fuel source |
|
|
A. Absorptive (fed or postprandial) state:
3. Amino Acids |
primarily taken up by the body cells for protein synthesis
liver takes up amino acids for protein synthesis |
|
|
Insulin:
When is it released? |
During Absorptive state
|
|
|
Insulin:
What does it bind to? |
to receptors on the membranes of target cells
|
|
|
Insulin:
What are the effects? |
Activates facilitated (carrier protein) diffusion of glucose into cells
Enhances glucose oxidation Stops glycogenolysis and enhances glycogen synthesis |
|
|
Post absorptive (fasting) state:
Primary goal? and Why? |
is to maintain blood glucose levels at about 5 mmol/L.
glucose must be maintained for the brain and the CNS, which will not use any other type of nutrient for energy |
|
|
Post absorptive (fasting) state:
This blood glucose level is maintained by? |
A. Making glucose available to the blood and
B. Glucose sparing processes so that glucose is available to the organs that need it. |
|
|
A. Sources of Blood Glucose
Blood Glucose can be obtained from |
1. Glycogenolysis in the liver
2. Glycogenolysis in skeletal muscle 3. Lipolysis in adipose tissue and liver 4. Catabolism of cellular protein |
|
|
B. Glucose Sparing Reactions
What happens? |
Almost every other organ in the body, except the brain switches to fats as its major source of energy, this ensures a continued glucose supply to the brain and CNS.
Body fat and amino acids are oxidised in the same pathways as CHO (glucose) this use of non-CHO sources for energy production is called glucose sparing. |
|
|
Starvation:
Day 1: |
liver glycogen falls to 10% of its normal concentration and stays pretty well constant at this
|
|
|
BGL during Starvation:
|
is constant 5mmol/L for about 4 weeks of a total fast
|
|
|
When does the rate of triglycerise metabolisim increase?
|
Once the supply of easily metabolised glycogen is exhausted
|
|
|
What increases with other forms of energy production other than glucose?
|
Ketone bodies start to rise in the blood
The amount of urea excreted in urine increases as proteins are degraded |
|
|
If fats are readily available, why are proteins degraded so fast??
|
brain has a very high metabolic rate
Glucose is available from the glycerol portion of triglycerides, but no glucose is available from the fatty acid portion. Proteins have more glucose making ability |
|
|
What happens during week 4-6 in starvation?
|
protein sparing starts, very little protein is used when the brain starts to use ketone bodies produced from fatty acids
|
|
|
What happens in severre stages of starvation once fat used?
|
the energy requirements comes totally from protein, muscle mass heavily drained —death inevitable 1/2 normal level of protein.
Enzymes no longer functio so any food is not digested. Pure glucose must be given intravenously |
