2e- Human Nutrition Flashcards
What are the necessary food groups
Carbohydrates Proteins Lipids Vitamins Minerals Dietary fibre Water
What are carbohydrates needed for
Source of energy
What are proteins needed for
Growth and repair
What are lipids needed for
Insulation and energy storage
What is dietary fibre needed for
Provides bulk for the intestine to push food through it
What is water needed for
For chemical reactions to take place in cells
What is vitamin A needed for
Night Vision
What is vitamin c needed for
- An essential part of collagen protein (skin hair and bones)
What does vitamin c deficiency lead to
Scurvy
What is vitamin D needed for
- absorbing calcium
- strong bones and teeth
What does vitamin D deficiency cause
Rickets
What is calcium needed for
- clotting of blood
- strong teeth and bones
What is iron needed for
To make haemoglobin which transports oxygen
How does age effect energy requirements
Energy needs of adults decrease as they age
How do activity levels effect energy requirements
The more active, the more energy required
How does pregnancy effect energy requirements
During pregnancy energy requirements increase due to the baby
What is the function of the mouth
- mechanical digestion
- saliva lubricates food
- amylase in saliva digests starch
What is the function of the oesophagus
- connects mouth to stomach
- contractions push food down
What is the function of the stomach
- food is mechanically digested by churning
- protease enzymes digest proteins
- hydrochloric acid kills bacteria
What is the function of the small intestine
- absorption of digested food molecules
- lined with villi to increase surface area for absorption
What is the function of the large intestine
- water is absorbed from material to produce faeces
What is the function of the pancreas
- produces digestive enzymes
- secretes enzymes into the small intestine
What is peristalsis
The contraction of two sets of muscles in the walls of the gut
What is the purpose of digestion
To break down large molecules into small ones that can be absorbed into the bloodstream
What is chemical digestion controlled by?
Enzymes
What is the role of amylase
Digests starch into maltose
What is the role of maltase
Breaks down maltose into glucose
Where is pepsin produced
In the stomach
Where is trypsin produced
In the pancreas
What is the role of lipase
Digests lipids into fatty acids and glycerol
Where is bile stored
Gall bladder
Where is bile produced
In the liver
What are the two main roles of bile
- to neutralise hydrochloric acid
- to emulsify fat
Where does absorption take place?
The ileum (small intestine)
How is the ileum adapted for absorption?
- very long
- large surface area
- highly folded surface with villi
What do microvilli do
Increase surface area for faster absorption of nutrients
How is a villus adapted for its function?
- microvilli
- think wall (1 cell thick)
- network of blood capillaries
What’s the function of the lacteal
Transports fatty acids and glycerol away from the small intestine
