Chapter 7- Energy Metabolism Flashcards
anabolic vs. catabolic reactions
anabolic- making of things (glycogen, triglyc, etc). Requires energy
catabolic- breaking down of things (glyco to glucose). Releases energy
energy metabolism
how the body obtains and uses energy from food to meet its needs
What percentage of the chemical enmergy in food is converted to energy in ATP?
50%
glycolysis- definition, where occurs, requires oxygen?
The breakdown of glucose to pyruvate. Occurs in the cytosol. Anaerobic
pyruvate can be used to make ____
Acetyl coA can be used to make ___, but not ____
glucose
fats, glucose
What is fatty acid oxidation?
the process of breaking down fatty acids to acetyl-coA
Where do most amino acids go in the energy pathway?
to pyruvate to then make glucose (glucogenesis)
Options for excess protein
- Fill normal needs first
- Increase protein oxidation (burn it off by converting AA to energy)
- Make ketone bodies (acetlyl coA) which stores as fat
Options for excess carbs
- Store as glycogen
- Increase carb oxidation to burn off
- Make into fat
Options for excess fat
Store as fat
glucogenesis
the making of glucose from non-carb sources like amino acids or glycerol
Why does fat provide more energy per gram?
it has more C-H bonds, so more spots for oxygens to be added. Glucose has water already so less C-H bonds
During feasting, carbs are broken down to ___ and used for ____
Broken down to glucose
Used for liver & muscle glycogen stores and also body fat stores
During feasting, fat is broken down into _____ and used for____
fatty acids
body fat stores
During feasting, protein is broken into _____ and used for ______
amino acids
body fat stores, loss of nitrogen in urine (urea), and body proteins
What is basal metabolism
the energy spent doing nothing. it’s 2.3rds of all energy a person needs
What two organs always have to have glucose?
RBCs and the brain
During fasting (2-3 hours after a meal) when dietary energy is gone,
- Liver and muscle glycogen stores are broken down to ____ and used for _____
- Body fat stores broken down to ____ and used for _____
- glucose and used for energy for brain, RBCs , and all other cells
- fatty acids and used for energy for everything except brain and RBCs and nerves.
During starvation, body protein is broken down to and used for
- It is broken down into amino acids
- AA are excreted in urea, turned to glucose, or turned to ketone bodies.
- The glucose is used for energy of water soluble cells (brain, RBCs and others). The ketones used for energy for the above or everything else.
During starvation, body fat is broken down to and used for
- broken down to fatty acids which can be used for energy for cells.
- the fatty acids can also be turned to ketone bodies which can be used for energy for either cells
What’s special about ketone bodies re: what they can be used for? Where are they produced? What derived from?
they can be used to provide energy for the water soluble things like the brain but also for energy for other cells
Produced in the liver and derived from fatty acids and acetyl-CoA
Affects of ketosis
Slows the rate of body protein breakdown
lowers blood pH
induced appetite loss
What’s the order of the body’s fuel backup plans?
- Glycogen stores
- Making glucose via glucogenesis (AA to pyruvate
- Use fat to make ketone bodies
What is one serving of alcohol?
1.2 oz of pure ethanol
