Week 03 - Fats Flashcards
Most fat is stored as _______
triaglycerols (TGS)
In order for fatty acids to be used for energy provision they must be transported to _____
Muscle
What splits the triaglycerols into fatty acids and glycerol
Hormone sensitive lipase
The hormone sensitive lipase is influenced by what 2 hormones?
epinephrine and insulin
Increased insulin results in a decreased regulation of …?
hormone sensitive lipase (HSL)
_____ is released from lipolysis into bloodstream and can be used by liver or muscle
Glycerol
To transport many fatty acids to muscle cell surface, you need _____ protein
albumin
Fatty acid transport is influenced by (3)?
- Amount of albumin
- Available binding sites on the albumin
- Blood flow to adipose tissue
Fat oxidation is highest at _______ intensity
Low-moderate intensity
LCHF diet is usually energy from ____% CHO and ___% fat
15-20% CHO, 60-65% fat
Ketogenic diet is ___% energy from CHO, and ____% from fat
5% CHO, 75-80% fat
What are two proposed benefits of LCHF diet?
- Decreased reliance on CHO oxidation
2. Increased capacity to oxidise fat
LCHF diet increases fat oxidisation during exercise by _____ times
2-3x
LCHF diet increases fat availability, mobilisation and transport by (4)?
- increased intramuscular triglyceride
- increase hormone sensitive lipase activity
- Increased expression of FAT/CD36 protein
- increased activity of carnitine palmitoyl
Negative metabolic adaptations of LCHF diet (2)?
- Decrease in CHO oxidation (2-3 times)
- Decreased in CHO availability, mobilisation and transport (by decrease muscle glycogen & down regulation of pyruvate dehydrogenase)
LCHF diet retools the body to increase capacity to….?
oxidise fats
LCHF diet has detrimental effects on…
CHO oxidation rates
Simple fat has 3 types…
Long chain: 12+ FA
Medium chain: 8-10 FA
Short chain: 6 or less FA
2 types of compound lipids…
Phospholipids, lipoproteins
Derived lipids are made up of…
Simple and compound fats (e.g. cholesterol)
Saturated fat have maximum amount of ____ that they can have
H+
The difference between saturated and unsaturated fat is the ____?
Bond
Saturated fat has a _____ bond
single (allows for stacking, no kink)
Unsaturated fat has a _____ bond
double (not stacking well, has kink)
Saturated fat is _____ at room temperature
solid
Unsaturated fat is ______ at room temperature
liquid
Monosaturated are _____ bond
single
Polysaturated are _____ bond
double
Trans fat saturated/unsaturated
unsaturated (double bond)
Trans fat is essential/non essential
non essential (want to keep low in diet)
Primary function of lipids (2)….
- Energy provision
- Fat oxidation in aerobic metabolism
Fat store amount compared to CHO store amount….
Fat stores contain 50x more than CHO stores
2 main sources of fat in the body…
- Adipose tissue
- Intramuscular triglycerides
(and plasma)
Steps of fat oxidation (6)
- Lipolysis
- Removal of FAs from adipose tissue
- Transport of fat into blood
- Transport of FAs into muscle
- Transport of FAs into mitochondria
- Transport of FAs in beta-oxidation and TCA cycle
BEFORE oxidation can occur, FAs must be (2)…
- Mobilised (separate glycerol and FAs)
2. Transported to site of oxidation
Lipolysis is the….
Breakdown of triglycerides to FAs and glycerol
The hormone sensitive lipase (HSL) breaks down….
ester bond -> initiates lipolysis
During rest, ____% of FAs stay in adipocytes
70%
During exercise, there is an increase in (3)…
- lipolysis
- catecholamines - epinephrine
- FA availability
During lipolysis, _____ is released from lipolysis into blood to the liver gluconeogenic substrate to form new _____
glycerol, glucose
albumin protein function?
Transports FA from adipocyte into blood after lipolysis
______ transports FA from adipocyte into blood
albumin
FA transport from adipocyte is dependent on (3):
- amount of albumin in the blood
- Available binding sites on the protein
- Blood flow to the adipose tissue
After FAs have left the adipose tissue they need to be transported into…
the muscle cell
Requires ???????? proteins to transport FAs into muscle cell
At least 2 FA binding proteins
Type ____ fibres have larger intramuscular stores than type ___
Type I, Type II
After FAs are in the muscle cell, transport into the mitochondria by ______ then ends up as _____
carnitine, fatty acyl CoA (NOT ACETYL)
Increase fat oxidation occurs as exercise duration _____
increases (due to depletion of muscle glycogen)
The primary fuel for low-intensity exercise>
fat oxidation
In high intensity exercise there is a _____ in fat oxidation, but lipolysis rate is …??
decrease, still high
Fat oxidation ______ by _____% in prolonged exercise
increases, 41%
CHO 1 hr prior to exercise -> increased insulin, reduction in FA availability = 30% less _______
fat oxidation
CHO -> ______ insulin -> _______ lipolysis -> ______ FA availability
CHO -> increase insulin -> decrease lipolysis -> decrease FA availability
Fasting _______ fat oxidation
increases
Fasting causes ______ performance and fatigue RESISTANCE
reduce
Short term high fat diet (3-5 days) _____ lipid availability, _____ glycogen stores, and ______ performance and fatigue resistance
Increases lipid availability
decreases glycogen stores
decreases performance and fatigue resistance
The effect of long term high fat diet is….
mostly unclear (may increase fat oxidation)
General fat intake recommendations is….
20-35% of daily intake (<10% saturated)
