Food Tests And Biomolecules Flashcards
What does Benedict’s solution test for
Reducing sugars
How to test for sugar!
Benedict’s in water in test tube
Sayer bath of 75
For 5 mins
Benedict’s colour change
Blue - Brick red
How to test for carbohydrates ?
5cm of food sample
Iodine
Colour change for carbs (iodine test)
Browny orange - blue black
Buriet test is for what ?
Proteins
Method for buirets test is ?
2cm sample
2cm buirets solution
Buiret colour change
Blue - pink/purple
For lipids what test ?
Ethanol
What is the emulsion test for lipids
Food sample
Ethanol
Distilled water
Emulsion test lipids colour change
Clear - cloudy white colour
What are enzymes ?
A protein molecule that acts as a biological catalyst
What’s a catalyst ?
Increases the rate of a chemical reaction while remaining unchanged
What’s a substrate ?
The molecule that enzymes act on
Why specific?
enzymes only act on certain substrates and not others
Active site
The region on which enzymes that binds the substrate
Product
End substance after reaction
Metabolism
Sun of all the chemical reactions in an organism
Denature
When the active site changes shape
This is irreversible
Why can denaturing occur ?
Very high or low temperatures
Change in pH
How is the placenta adapted for rapid exchange ?
-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)
Absorption?
The passage of small molecules into vessels that can transport them into the body through blood
Adaptions that allow for absorption in the small intestine?
- 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
The digestive system is what?
Is a group of organs that work together to break down (digest) and absorb food
What are proteins for ?
Repair, growth
What are lipids for ?
Insulation and energy
What are carbohydrates for ?
Energy (respiration )
What are subunits of carbohydrates?
Glucose
What are subunits of proteins ?
Amino acids
What element do proteins also contain that lipids and carbohydrates do not?
Nitrogen
(O,C,H,N)
What does it mean to emulsify fats?
Break them up into smaller ones
What does the mouth do ?
Mechanical digestion
Chemicals produced in the mouth ?
Amalyse - breaks down starch
Function of the oesophagus?
Peristalsis - muscle contraction to push food to the stomach
Stomachs function?
Physical digestion - churning
Chemicals produced in the stomach?
Hydrochloric acid
What’s the function of the liver ?
To produce bile
What is biles job?
To neutralise the stomach and emulsify fats
What’s the purpose of the gallbladder ?
To store bile
Function of the pancreas ?
Chemical digestion - produces enzymes
Chemical reactions in the pancreas are what ?
All biomolecules and subunits
Function of the small intestine ?
Absorb food into the blood stream
What chemicals are produced in the small intestine ?
All enzymes + subunits
Function of the large intestine ?
To absorb water into the blood stream
Chemicals produced in the large intestine?
Some minerals
Function of the rectum and anus?
Egestion
Waste storage
What’s the first required practical ?
Place food In test tube and add regent for food tests
What the second require practical ?
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
What the Locke and key theory?
Enzymes are locks , substrates are keys that fit into active site eg amalyse (enzyme ) and starch (substrate)
