Metabolic Fuels Flashcards
Define Metabolsim
Sum of the chemical reactions that take place within each cell of a living organism
What are the four main pathways dietary components are metabolised in cells
- Biosynthetic
- Fuel storage
- Oxidative processes
- Waste disposal
Define anabolic
Synthesise larger molecules from smaller components
Define catabolic
Break down larger into smaller
Is biosynthetic pathway anabolic or catabolic
Anabolic
Is fuel storage pathway anabolic or catabolic
Anabolic
Is oxidative pathway anabolic or catabolic
Catabolic
Is waste disposal anabolic or catabolic
Either
What does catabolism provide
Energy for cell processes from ‘fuel’ molecules
Provides energy for anabolism
What is the primary (but not only way) which catabolism provides energy for anabolism
Oxidative Phosphorylation
How is adipose tissue specialised for energy
85% fat
Storage of energy-rich molecules
How is liver specialised for energy
Metabolically active
E.g. Gluconeogenesis (removal of toxins)
What are the 3 main dietary energy sources
Carbohydrates
Lipids
Proteins
How does the body store dietary fuels
Adipose tissue (fat) - only approx. 15% water
Carbohydrates as glycogen in liver and muscles
Protein in muscles (80% water)
What are the three way things happen to excess energy intake
Stores as triglycerides in adipose
Store as glycogen
Store as protein
Approximately how much weight is stored as triglycerides in adipose
15kg
Approximately how much weight is stored as glycogen in liver and muscle
200g in liver
80g in liver after overnight fast
150g in muscle
Approximately how much weight is stored as protein in muscle
6kg
How much energy is there per gram in carbohydrate
4kcal/g
How much energy is there per gram in protein
4kcal/g
How much energy is there per gram in alcohol
7kcal/g
How much energy is there per gram in lipid
9kcal/g
What is Basal Metabolic Rate (BMR)
A measure of the energy required to maintain non-exercise bodily functions
(Energy needed to stay alive at rest)
How does hypothyroidism affect BMR
Thyroid hormones regulate metabolic rate, core body temperature, appetite, sympathetic activity etc.
What factors can affect a decreasing BMR
Age
Gender
Dieting/Starvation
Hypothyroidism
Decreased muscle mass
Why does muscle mass effect BMR
Muscle cells require more energy to maintain than fat cells
(As we get older tend to loose fat, explains why BMR tends to decrease with age)
What factors can increase BMR
Body weight (BMI)
Hyperthyroidism
Low ambient temperature
Fever/infection/chronic disease
What are the NHS nutrition guidelines recommended for patients in kCal/kg/d for anyone who are not severely ill or injured, nor at risk of re-feeding syndrome
25-35 kCal/kg/day
In grams how much glucose does the brain require a day
150g
Define gluconeogenesis
During longer period of fasting/starvation, glucose must be formed form non-carbohydrate sources
After an overnight fast what happens to the body
Decrease insulin
Glycogenolysis
What happens after 2-4 days of starvation
Decrease insulin
Increase cortisol
Lipolysis and Proteolysis
What does gluconeogenesis use
Lactate
Amino acids - muscle, intestine, skin
Glycerol - fat breakdown
After more than 4 days of starvation what happens to the body
Liver converts ketones from fatty acids
Brain adapt to using ketones
BMR decreases
Define malnutrition
A state of nutrition with a deficiency, excess or imbalance of energy, protein or other nutrients, causing measurable adverse effects
What is re-feeing syndrome
Danger of feeding too fast
Re-distribution of phosphate, potassium, magnesium etc. due to insulin
Switch back to carbohydrates as the main fuel source requires phosphate and thiamine
What is the key information about vitamin C
Heat liable
Collagen synthesis
Improve iron absorption
Antioxidant
What is the key information of vitamin B12
Protein synthesis
DNA synthesis
Regenerate folate
Fatty acid synthesis
Energy production
What does vitamin B1 (Thiamine) do
Help with energy production in your body
What does vitamin B2 (Riboflavin) do
Helps with energy production in your body
Helps your body use other B vitamins
What does vitamin B3 (niacin) do
Helps your body to use protein, fat and carbohydrate to make energy
Help enzymes work properly in your body
What does biotin do
Allows your body to use protein, fat, carbohydrate from food
What does vitamin B6 do (pyridoxin)
Helps your body to make and use protein and glycogen which is the stored energy in your muscles and liver
Helps form haemoglobin which carries oxygen in your blood
What does vitamin B12 (Cobalamin) do
Works with the vitamin folate to make DNA
Helps to make healthy blood cells
Low levels of vitamin B12 can cause a type of anaemia
Keeps nerves working properly
What does folate (folic acid) do
Helps produce and maintain DNA and cells
Helps to make red blood cells and prevent anaemia
Getting enough folic acid lowers the risk of having a baby with birth defects like spina bifida
What does vitamin C do
May help prevent cell damage and reduce risk of certain cancers, heart disease and other disease
Collagen synthesis (helps heal cuts and wounds and keeps gums healthy)
Keeps immune system healthy
Increases amount of iron body absorbs from food
What does vitamin A do
Helps see at day and night
Protects you from infections by keeping skin and other body parts healthy
Promotes normal growth and development
What does carotenoids do
Not vitamins - can turn into vitamin A in the body
Act as antioxidants which protect body from damage caused by harmful molecules caused by free radicals
What does vitamin D do
Increases the amount of calcium and phosphorus your body absorbs from foods
Deposits calcium and phosphorus in bones and teeth, making them stronger and healthier
Protects against infections by keeping your immune system healthy
What does vitamin E do
Helps maintain a healthy immune system
Acts as antioxidant and protects cells from damage
What does vitamin K do
Makes proteins that cause our blood to clot
Involved in making body proteins for your blood, bones and kidneys
How much protein should be consumed a day
0.8g/kg/day
What is the maximum amount of saturated fat consumed a day
Man 30g
Woman 20g
What is the maximum amount of energy consumed by free sugars a day
5%
What is the maximum amount of sodium (salt) a day
2.4g sodium
6g salt
How much units is recommended a week
14 units (over more than 3 days)
