Food Tests And Biomolecules

Question 1

What does Benedict’s solution test for

Answer 1

Reducing sugars

Question 2

How to test for sugar!

Answer 2

Benedict’s in water in test tube
Sayer bath of 75
For 5 mins

Question 3

Benedict’s colour change

Answer 3

Blue - Brick red

Question 4

How to test for carbohydrates ?

Answer 4

5cm of food sample
Iodine

Question 5

Colour change for carbs (iodine test)

Answer 5

Browny orange - blue black

Question 6

Buriet test is for what ?

Answer 6

Proteins

Question 7

Method for buirets test is ?

Answer 7

2cm sample
2cm buirets solution

Question 8

Buiret colour change

Answer 8

Blue - pink/purple

Question 9

For lipids what test ?

Answer 9

Ethanol

Question 10

What is the emulsion test for lipids

Answer 10

Food sample
Ethanol
Distilled water

Question 11

Emulsion test lipids colour change

Answer 11

Clear - cloudy white colour

Question 12

What are enzymes ?

Answer 12

A protein molecule that acts as a biological catalyst

Question 13

What’s a catalyst ?

Answer 13

Increases the rate of a chemical reaction while remaining unchanged

Question 14

What’s a substrate ?

Answer 14

The molecule that enzymes act on

Question 15

Why specific?

Answer 15

enzymes only act on certain substrates and not others

Question 16

Active site

Answer 16

The region on which enzymes that binds the substrate

Question 17

Product

Answer 17

End substance after reaction

Question 18

Metabolism

Answer 18

Sun of all the chemical reactions in an organism

Question 19

Denature

Answer 19

When the active site changes shape
This is irreversible

Question 20

Why can denaturing occur ?

Answer 20

Very high or low temperatures
Change in pH

Question 21

How is the placenta adapted for rapid exchange ?

Answer 21

-diffusion/active transport
- rapid exchange in and out of blood
-low to high concentration for molecule diffusion
-good blood supply (for organ function)
-thin placenta walls (faster diffusion)
-Large SA (for faster diffusion)

Question 22

Absorption?

Answer 22

The passage of small molecules into vessels that can transport them into the body through blood

Question 23

Adaptions that allow for absorption in the small intestine?

Answer 23

• large SA (inner surface covered in villi and microvilli)
  -thing cell walls ( villus only one cell thick)
  -good blood supply (each villus supplied with blood + maintains concentration gradient

Question 24

The digestive system is what?

Answer 24

Is a group of organs that work together to break down (digest) and absorb food

Question 25

What are proteins for ?

Answer 25

Repair, growth

Question 26

What are lipids for ?

Answer 26

Insulation and energy

Question 27

What are carbohydrates for ?

Answer 27

Energy (respiration )

Question 28

What are subunits of carbohydrates?

Answer 28

Glucose

Question 29

What are subunits of proteins ?

Answer 29

Amino acids

Question 30

What element do proteins also contain that lipids and carbohydrates do not?

Answer 30

Nitrogen (O,C,H,N)

Question 31

What does it mean to emulsify fats?

Answer 31

Break them up into smaller ones

Question 32

What does the mouth do ?

Answer 32

Mechanical digestion

Question 33

Chemicals produced in the mouth ?

Answer 33

Amalyse - breaks down starch

Question 34

Function of the oesophagus?

Answer 34

Peristalsis - muscle contraction to push food to the stomach

Question 35

Stomachs function?

Answer 35

Physical digestion - churning

Question 36

Chemicals produced in the stomach?

Answer 36

Hydrochloric acid

Question 37

What’s the function of the liver ?

Answer 37

To produce bile

Question 38

What is biles job?

Answer 38

To neutralise the stomach and emulsify fats

Question 39

What’s the purpose of the gallbladder ?

Answer 39

To store bile

Question 40

Function of the pancreas ?

Answer 40

Chemical digestion - produces enzymes

Question 41

Chemical reactions in the pancreas are what ?

Answer 41

All biomolecules and subunits

Question 42

Function of the small intestine ?

Answer 42

Absorb food into the blood stream

Question 43

What chemicals are produced in the small intestine ?

Answer 43

All enzymes + subunits

Question 44

Function of the large intestine ?

Answer 44

To absorb water into the blood stream

Question 45

Chemicals produced in the large intestine?

Answer 45

Some minerals

Question 46

Function of the rectum and anus?

Answer 46

Egestion Waste storage

Question 47

What’s the first required practical ?

Answer 47

Place food In test tube and add regent for food tests

Question 48

What the second require practical ?

Answer 48

Place amylase into test tube with ph buffer , iodine in spotting tile , add starch to solution wait, add solution to iodine, every 30 seconds add , until iodine remains orange

Question 49

What the Locke and key theory?

Answer 49

Enzymes are locks , substrates are keys that fit into active site eg amalyse (enzyme ) and starch (substrate)