9 Flashcards
Function of Carbohydrates
Energy
Function of proteins
growth and repair
Fats
For energy / makes membranes
Functions of vitamins
In small amounts for cells to work properly
Function of minerals
Small amounts to make body chemicals
Functions of Fibre
Keep bowels working properly
Water
For chem reactions.
Function of the mouth
Food is chewed and mixes with saliva
Oesophagus
Joins mouth to the stomach
Stomach
‘bag with strong muscles’ food mixed with protease enzymes.
Liver
Makes bile juice - neutralises acid
Pancreas
Produces different enzymes and acids
Small intestine
A long tube which completes digestion and absorbs nutrients from food.
Large intestine
A long tube. Water is absorbed from food
Rectum
Faeces are stores before leaving the body.
Gall bladder
stores and concentrates bile salts before theyre secreted into the duodenum
Specialisation of the mouth
TEETH
These chew - mech digestion
Tongue mixes food w saliva aiding chem digestion
Oesophagus specialisation
contractions - peristalsis.
Stomach specialisation
hydrochloric acid
enzyme pepsin
Mechanical digestion
Breakdown large masses of food into smaller masses
- chewing with teeth and tongue
- bile salt
Chemical digestion
Denaturing of proteins using acid baths (HCl)
What type of molecule is broken into amino acids?
Proteins
What happens in disaccharide deficiency?
- Intolerance to sugars
- Lack of lactase enzyme – unable to break down lactose into glucose and galactose.
- Bacteria in the gut break down lactose as it reaches the colon.
- The fermentation gases create unpleasant symptoms such as abdominal cramps, nausea and vomiting.
- The altered osmotic potential of the colon prevent efficient reabsorption of water and causes diarrhoea
Name the process by which substances such as amino acids move into the blood stream from small intestine
Diffusion
How are villi adapted to make digestion more efficient
Large surface area
Thin walls - shorter distance for molecules to travel into blood
Do fats or carbs have more energy?
Carbs have 2x more energy per gram
What happens after food is broken down?
Used in cell respiration to make ATP
How is energy content in food worked out?
Substance Mass
What is BMI
Body mass Index
Limitations of BMI
When muscle weighs more then fat
Doesnt account for other tissues
Doesnt measure fat around organs which is a sign of healthy weight.
BMI rate of underweight
12-18.5
Healthy BMI
18.5-25
Overweight BMI
25.5-29
Obese BMI
30-39
two people with a mass of 90kg
- one is seen as healthy
- one is seen as obese
why?
the obese persons BMI is higher, they are shorter meaning their mass is due to body fat and not bone/muscle.
Sources of Carbs
Role of carbs
Potato, rice, pasta
Starch used as main substrate for cellular respiration to make Atp
Sources of proteins
Role
Red and white meat, fish, nuts
Growth and repair of cells
Source of Lipid
Role
Cheese, yoghurt and chocolate
Energy store, makes up cell membranes
Cholesterol used to make steroids
Vitamin ROLES AND SOURCE
C
A
K
B
C - citrus fruits : tissue growth and repair
K - Green leafy veg : blood clotting
A/B - dairy/fish/liver : maintains teeth/bones/skin/brain function
Minerals
Iron
Calcium
Phosphate
Iron - Red meats and green leafy veg : Haemaglobin for oxygen transport.
Calcium : Milk Sun - Bone formation
Phosphate : Processed meat and cola - ATP synthesis
Sodium : Salt - Nervous system function
Potassium : Fruit banana : NS function
Water intake and what does it do
From food and drink
Main bodily fluid
Fibre intake and what it does
Vegetables and salads
Allows bowels to work properly and prevents constipation
Function of Pepsin
Breaks down proteins
Function of trypsin
Digests proteins
Small intestine
How is the small intestine adapted for absorption
Large surface area
Rich blood supply
Short diffusion pathway
