L23 - nutrition

Question 1

why is nutrition important

Answer 1

• develop and maintain state of health
• include balance and moderation in lifestyle
• avoids cancer and disease

Question 2

what is nutrition

Answer 2

process where we take up substances from the food

Question 3

types of substances taken in as nutrients

Answer 3

• macromolecules like proteins, fats, carbohydrates
• micromolecules - mineral and vit
• water

Question 4

why do we need to eat

Answer 4

-need energy from food for metabolism, muscle activity etc

Question 5

3 main processes where energy is needed

Answer 5

BMR - no of calories needed for body at rest to do involunatry function

thermic effect of food - digestion and absorption

physical activity

other factors like body temps, pregenancy, growth, age, health

Question 6

how is glucose metabolised

Answer 6

• 1. glycolysis into pyruvate
     
     2. into krebs cycle in mitochondira
     3. in ETC to produce 36/38 ATP

Question 7

what parts of the body used glucose

Answer 7

brain and RBCs and muscle and liver

Question 8

what parts of the body use fat as an energy source

Answer 8

-everything else? apart from brain, spinal cord and RBCs

Question 9

why is weight loss difficult (losing the fat )

Answer 9

it needs large amount of O2 to metabolise and its insoluble in water. so it cant be accessed

Question 10

functions of using fats

Answer 10

-incoporation in body structures
-protection
insulation
-satiety
-fat soluble vit
energy storage - no limit

Question 11

how many ATPs does fat make

Answer 11

130

Question 12

fucntions of proteins

Answer 12

• making new proteins
• growth and repair of tissue
• not main function but can be oxidised to make energy ans urea is extreted

Question 13

what is nitrogen balance

Answer 13

N2 intake (NI) - N excretd(NE)
- in adults, its in EQB

Question 14

why is positive N2 balance is good

Answer 14

-allowa for growth, recovery and pregnancy

Question 15

why is negative N2 balance is bad

Answer 15

starvation, trauma, infection, tissue destruction

Question 16

types of non energy supplier nutrients

Answer 16

dietary fibre- non digestible in the gut

Question 17

types of dietary fibre and importance of it

Answer 17

-insoluble - provides bulk in the gut so prevents constipation and slowing down digestion
-soluble - absorbs water and lowers cholestral and reduces risk for bowel cancer
-

Question 18

types of micronutirents

Answer 18

• water soluble - for enxymes cofactors and protein synthesis
• fat soluble like A,E,K,D
• minerals as ions

Question 19

why is water important

Answer 19

-prevents dehydration, solvent, metabolism and excretion

Question 20

how do we maintain our body mass

Answer 20

involves neuroendocrine regulation of feeding using appetite and satiety

Question 21

what regulate energy intake as well as hunger and satiety centre

Answer 21

hypothalamus and brain stem

Question 22

is it in hungry or satiety state when glucose levels falls

Answer 22

hungry

Question 23

hormone stimulating appetite

Answer 23

ghrelin

Question 24

hormones inhibiting appetite

Answer 24

CCK, insilun, leptin

Question 25

factors contributing to the loss of appetite

Answer 25

physiological like infection and disease and psychological like stress

Question 26

how to control our metabolism

Answer 26

balance between storing energy in fed state (anabolism) and releasing energy in fasted state (catabolism)

Question 27

where is fat stored

Answer 27

adipose tissue

Question 28

preferred fuel and why for the body

Answer 28

- carbohydrates like glucose since more ATP can be generated in the same amount if fats were used - using fats would take a longer time to be oxidised

Question 29

why cant FFAs be used by RBCS and the brain

Answer 29

for RBCs- they dont have mitochondria so the fats cant be oxidised and go through krebs cycle - for brain, fats are lipids and in the brain, it has blood brain barrier where lipids cant go in

Question 30

what is blood brain barrier

Answer 30

highly selective permeable barrier | - have TJs and seperates blood from extracellular fluid in CNS

Question 31

cons of using FAs over glucose as a energy source for brain

Answer 31

- needs more O2 - Beta oxidation generates superoxide which can be harmful for cells like neurones - ATP generation slower than glucose

Question 32

why is fats used over glucose when doing low intensity exercise

Answer 32

-during this exercise, we use slow twitch muscles (type 1 i think?) which uses fats

Question 33

why is glucose used over fats when doing high intensity exercise

Answer 33

-we use fast twitch muscles (type 2?) which uses more glucose than fats

Question 34

origins of obesity

Answer 34

- inherited through mutations | - acquired like stress, aging, overeating

Question 35

what happens when u eat more calories than them burning off

Answer 35

usually, glucose and proteins from diet can be used in krebs cycle to produce energy - but when the energy is not needed, it's converted into triglycerides

Question 36

what does too much insulin do to the triglycerides

Answer 36

when you consume glucose, insulin is produced. this inhibits the breakdown of triglycerides into glycerol cos the glycerol can be used to make more glucose

Question 37

treatments of obesity

Answer 37

restrict food intake - exercise - drugs

Question 38

what is stravation

Answer 38

deprivation of calories -consumes our tissues to continue energy production -

Question 39

mechanisms used in starvation

Answer 39

gluconeogenesis - AAs converted and glycerol used for making glucose -ketogenesis - FA becomes keto bodies to be used by the brain

Question 40

what happens using muscle and fat as our energy source in starved state

Answer 40

- breakdown of mucles releases AAs - breakdown of fats released glycerol - both used to make glucose

Question 41

con of using muscle and fat as our energy source in starved state

Answer 41

-can deplete afterwards

Question 42

what is ketone bodies and how is it produced

Answer 42

- water soluble product produced from the breakdown of FA in the liver

Question 43

why is ketone bodies useful in starved state

Answer 43

it can cross blood brain barrier so it can supply energy for the brain