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Flashcards in Nutrition Deck (41)
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1
Q

What is photosynthesis

A

The process where plants make their own food.

Light energy from the sun is absorbed by chlorophyll to convert CO2 and water to glucose and oxygen.

2
Q

Equation for photosynthesis

Chemical and word

A

Water + carbon dioxide–> glucose + oxygen

6H2O + 6CO2–> C6H12O6 + 6O2

3
Q

What factors affect the rate of photosynthesis?

A

CO2- it is a reactant so if you lower the amount of CO2, it becomes a rate limiting factor.

Light intensity- if the amount of light is less, there is less energy provided so the reaction slows down.

Temperature- cold temp/high = little/ no photosynthesis as enzymes are not at optimum temp.

4
Q

Waxy cuticle

A

Thin waxy layer of protection which prevents water loss, but does not prevent sunlight from entering.

5
Q

Upper epidermis

A

Thin transparent layer so light can easily reach the palisade layer.

6
Q

Spongy mesophyll

A

Full of air spaces to increase the surface area for diffusion of gases.

7
Q

What are the basic structures in leaves?

A

Large surface area: allows them to absorb more sunlight
Thin: shorter distance for CO2 to diffuse through
Opening and widening of stoma: increases the amount of CO2 entering.

8
Q

What minerals do plants need and why?

A

Magnesium ions= produce chlorophyll which traps sunlight for photosynthesis
Nitrate ions: needed to make amino acids and to make protein.

9
Q

Describe experiment to investigate rate of photosynthesis

A

1) place pond weed under water
2) vary light intensity (different lamp distances) and amount of CO2 (soda lime) and measure amount of O2 gas.
* lamp far away=little oxygen=less photosynthesis
* little CO2= less oxygen= less photosynthesis

10
Q

What is a balanced diet

A

A diet that supplies proteins, fats, lipids, carbohydrates, water, minerals, vitamins and dietary fibre in the correct quality and proportion.

11
Q

Source and function of carbs

A

Pasta, rice, bread and vegetables

–> immediate energy

12
Q

Protein sources and function

A

Red meat, fish, nuts and beans

Helps with growth and repair of cells and muscles.

13
Q

Fats sources and functions

A

Eggs, dairy meat

Long germ energy source and is used to protect and insulate important organs.

14
Q

Vitamin A sources and functions

Deficiencies

A

In Liver and orange veggies.

-so cells can produce pigments
-embryos can develop properly
-so immune system can maintain the integrity of skin and mucus cells in the lining of the breathing and digestive system.
Deficiencies= causes poor vision in the dark

15
Q

Vitamin C sources and functions

Deficiencies

A

Oranges and citrus fruits

  • helps cells stick together
  • makes collagen
  • growth and repair of tissues

Deficiencies - bleeding gums and scurvy

16
Q

Vitamin d sources and function

Deficiencies

A

Salmon, mackerel, eggs

Helps the body with the absorption of calcium

Cam develop rickets if deficient

17
Q

Sources and function of iron

Deficiencies

A

Red meat, liver, green and leafy veggies

Helps produce haemoglobin needed by RBC.

Deficiencies: anaemia= weak and tired

18
Q

Sources functions of Calcium

Deficiencies?

A

Dairy such as milk, cheese , yoghurt

Production of strong teeth and bones
Involved in chemical reactions of blood clotting and muscle contraction.

19
Q

Why do we need water in our diets?

A

All cells require oxygen to function and we lose 2-3 quarters of water a day.

20
Q

Dietary fibre sources and function

Deficiency

A

Cereals, bread, rice, beans and nuts

Assists with bowel movement in the colon
Deficiencies= constipation

21
Q

What do energy requirements depend on?

A
Height 
Weight 
Age
Pregnancy 
Lifestyle
22
Q

What is the first stage of digestion?

A

Mouth
Mechanical: teeth cut large and complex molecules of food into smaller snd less complex ones to create a larger surface area for enzymes to act on.

Chemical: salivary amylase breaks down starch into maltose and moistens food to reduce friction.

23
Q

Where do food molecule go after the mouth and what happens there

A

Oesophagus

Peristaltic movement= waves of muscular contractions to push food down to the stomach
Mucus= released by goblet cells to reduce friction

24
Q

What happens in the stomach

A
HCL= released to kill bacteria and to provide optimum pH for pepsin
Mechanical= peristaltic movements mix up contents of food to make them smaller
Chemical= protease is released to break large molecules of protein into smaller amino acids and peptides.
25
Q

Adaptations of stomach

A
  • Muscular walls that can stretch
  • 2 tight rings of muscle at top and bottom to control entry and exit of materials
  • cells in the stomach secrete mucus to protect its lining
  • as material leaves, alkaline juices are released to neutralise material and prevent damage to small intestines
26
Q

Small intestines

A

Duodenum- partially digested food enters here and is absorbed out to the body
Neutralisation= stomach acid is neutralised by pancreatic juices.
Enzymes= enzymes are added to complete digestion

27
Q

Large intestines role in digestion

A
Colon= where most of the water is reabsorbed, leaving behind faeces 
Rectum= where faces are stored
28
Q

What does the pancreas do?

A

Releases enzymes
Amylase= starch–> maltose
Protease= protein–> amino acids and peptides
Lipase= fats–> fatty acids and glycerol

They realises alkaline juices to neutralise stomach acid to prevent damage to small intestines.

29
Q

What is ingestion?

A

The process of material being taken in

30
Q

What is digestion

A

The process of larger and complex food being broken down into smaller and less complex molecules by mechanical and chemical digestion

31
Q

What is absorption

A

This is when small molecules from digestion pass into the blood supply of the ileum (by diffusion or active transport)

32
Q

What is assimilation

A

When small molecules are absorbed into the blood are passed out to body cells to make chemicals needed by the body.

33
Q

What is egestion

A

The removal of undigested material, dead cells and bacteria from the body.

34
Q

What is peristalsis

A

Waves of muscular contractions to he,o move food move down the oesophagus. It’s also a form of mechanical digestion in the stomach.

35
Q

Amylase

A

Starch to maltose

36
Q

Maltase

A

Maltose to glucose

37
Q

Protease

A

Protein to amino acids and peptides

38
Q

Lipase

A

Fatty acids and glycerol

39
Q

What is the role of the ileum?

A

It is the last region of digestion and is where the final process of absorption takes place. (E.,g Molecules such as glucose, amino acids, vitamins, minerals, fatty acids and glycerol)

40
Q

How are villi adapted to their function?

A

Folded surface area- large surface area
Finger like projections= villi
Micro villi= even larger surface area
Rich blood supply because of capillaries allow diffusion of food to take place quickly
1 cell thick= shortens diffusion distance.

41
Q

How do you calculate energy content in food sample

A

Burn a piece of food under tube of water
Calculate temperature rise
Change in temp * mass of water * 4.18
= energy in joules