Section 2 - Human Nuturition Flashcards Preview

Edexcel GCSE Biology > Section 2 - Human Nuturition > Flashcards

Flashcards in Section 2 - Human Nuturition Deck (37)
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1
Q

What elements do carbohydrate molecules contain (3)

A
  • Hydrogen - Oxygen - Carbon
2
Q

Starch and glucose are large, …… carbohydrates, made up of many smaller units, joined together in a …. ……

A
  • complex - long chain
3
Q

What are proteins made up of (2)

A
  • Amino Acids
  • Long chains
4
Q

What elements do amino acids contain (4)

A
  • Carbon - Nitrogen - Hydrogen - Oxygen
5
Q

What are lipids made up of (2)

A
  • Fatty acids - Glycerol
6
Q

What elements do lipids contain (3)

A
  • Carbon - Hydrogen - Oxygen
7
Q

Describe how to test for glucose (5)

A
  • Benedict’s test
  • Add blue Benedict’s reagent to a sample and heat it
  • Make sure the solution doesn’t boil
  • If glucose is present, it will forma a coloured precipitate
  • The higher the conc of glucose, the further the colour change goes (use to compare)
8
Q

For the Benedict’s test, what are the colours for varying conc’s of glucose (3)

None -

Low -

High

A
9
Q

Describe how to test for starch (2)

A
  • Add iodine solution
  • If starch is present, sample changes from brown/orange to a dark, blue/black colour
10
Q

What are the 5 essential nutrients (5)

A
  • Carbs
  • Protein
  • Fats
  • Vitamins & Minerals
  • Water

+ Fibre

11
Q

What is the function of Vitamin A, C and D and what are they found in (6)

A

Vitamin A - Liver - Improve vision, keep your skin and hair healthy

Vitamin C - Oranges - Prevent scurvy

Vitamin D - Eggs - Needed for calcium absorption

12
Q

What 2 mineral ions de we need, what are their functions and what can we find them in (6)

A

Calcium - Milk, cheese - make bones and teeth

Iron - Red meat - needed to make haemoglobin for healthy blood

13
Q

What is dietary fibre’s function and what is it found in (2)

A
  • Aids the movement of food through the gut
  • Wholemeal bread
14
Q

Describe an experiment to show how much energy is in food (9)

A
  • Find a food that burn’s easily; a peanut
  • Weigh a small amount of the food and then skewer it with a mounted needle
  • Add 25cm3 of water to a boiling tube, and measure its temperature
  • Set fire to the food using a bunsen burner
  • Hold the burning food under the boiling tube until it goes out
  • Relight and hold again, until no longer possible
  • Measure the temperature of the water

Use : 25 x temp change x 4.2 = energy in food

Use : energy/mass = energy per gram of food (J/g)

15
Q

Describe a way to make the energy from food practical more accurate (2)

A
  • Insulate the boiling tube with foil
  • Minimises heat loss and keeps more energy in the water
16
Q

Why are digestive enzymes needed in the body (3)

A
  • Digestive enzymes break down big insoluble molecules into smaller soluble ones
  • Starch, proteins and fats are too big to pass through the walls of the digestive system
  • Digestive enzymes allow starch, proteins and fats to be soluble and pass through the walls of the digestive system to be digested
17
Q

The digestive enzyme ……. converts starch into …….

A

Amylase

Maltose

18
Q

The digestive enzyme ……. converts maltose into …….

A

maltase

glucose

19
Q

The digestive enzyme ……. converts proteins into …….

A

protease

amino acids

20
Q

The digestive enzyme ……. converts lipids into ……. and ……..

A

Lipase

Fatty acids and glycerol

21
Q

Where is bile produced, stored and released into (3)

A

Produced - liver

Stored - gall bladder

Released into small intestine

22
Q

What does bile do (3)

A
  • Bile neutralises hyrdochloric acid in the stomach
  • Allowing enzymes in the small intenstine to work properly
  • Bile emulsifies fats, making digestion faster as there is a bigger surface area of fat
23
Q

The ………… …….. is another name for the gut (1)

A

alimentary canal

24
Q

Label all 10 partS (10)

A

A - Mouth

B - Oesophagus

C - Liver

D - Stomach

E - Pancreas

F - Large Intestine

G - Small Intestine

H - Appendix

I - Anus

J - Gall bladder

25
Q

What is A and what is its purpose (3)

A
  • Mouth
  • Salivary glands produce amylase enzymes in the saliva
  • Teeth break down food mechanically
26
Q

What is B and what is its purpose (2)

A
  • Oesphoagus
  • Muscular tube that connects the mouth and stomach
27
Q

What is C and what is its purpose (2)

A
  • Liver
  • Where bile is produced
28
Q

What is D and what is its purpose (4)

A
  • Stomach
  • Pummels food with its muscular walls
  • Produces protease enzyme, pepsin
  • Produces HCL;

to kill bacteria

to give the right pH for the protease enzyme to work

29
Q

What is E and what is its purpose (3)

A
  • Pancreas
  • Produces protease, amylase and lipase enzymes
  • It releases these into the small intestine
30
Q

What is F and what is its purpose (2)

A
  • Large intestine
  • Where excess water is absorbed from the food
31
Q

What is G and what is its function (3)

A
  • Small intestine
  • Uses protease, amylase and lipase enzymes to complete digestion
  • Where nutrients are absorbed out of the alimentary canal into the body
32
Q

What is I and what is its purpose (2)

A
  • Anus
  • Where faeces are egested
33
Q

What is J and what is its purpose (2)

A
  • Gall bladder
  • Where bile is stored
34
Q

What is peristalsis (3)

A
  • Waves of circular muscle contractions
  • Allowing food to squeeze through your gut and not get clogged
  • Occurs in muscular tissue all the way down the alimentary canal
35
Q

Describe the digestive process (5)

A
  • Ingestion : Food taken into your mouth
  • Digestion : Break down of large, insoluble molecules to smaller soluble ones. Can be mechinal (e.g teeth) or chemical (e.g bile)
  • Absorption : Digested food molecules are absorbed in the small intestine; water mainly in the large. Absorption is he process of moving molecules through the walls of the intestines in the blood
  • Assimilation : When digested molecules bcome part of cells (e.g digested amino acids assimilated, used by cells to make cellular proteins
  • Egestion : All the undigested molecules form faeces, you get rid of them through the anus.
36
Q

Explain how villi in the small intestine help with absorption (6)

A
  • Villi found on duodenum and ileum
  • It’s very long, time to break down and absorb all the food before it reaches the end
  • Large surface area for absorption, because the walls are covered with millions of villi
  • Villi are finger like projections which increase surface area
  • Each cell on the surface of a villus has microvilli, increasing the surface area even more
  • Villi have a single permeable layer of surface cells and a very good blood supply to assist quick absorptionn.
37
Q

Label the two missing parts and give their function (4)

A

Duodenum - Recieves partially digested food from the stomach, crucial role in chemical digestion

Illeum - mainly to absorb vitamin B12 and bile salts