Energy for life: Digestion Flashcards
(67 cards)
What are the function of carbohydrates?
Fuel for respiration
What is the function of protein? [2 points]
- growth and repair of tissues
- fuel for respiration
What is the function of lipids/fats? [3 points]
- Store of energy
- Thermal and electric insulation
- fuel for respiration
What enzyme breaks down starch?
Amylase
What affects enzyme activity? [4 points]
- Temperature
- pH
- Substrate concentration/ enzyme concentration
What is the food test for Glucose? (And explain what cilour it turns and how to prepare it)
Benedict solution, which start blue and then turns red or orange is startch is present.
Must be heated.
How is the vili adapted for absorption of molecules? [3 points - list and explain for all points]
- Has microvili for a large surface area
- Thin walls for short diffusion distance
- Near blood vessels > good blood supply means there is a high concentration gradient, which means diffusio happens very quickly.
What is the role of bile? [2 points]
- Emulsifies fats
- Neutralises stomach acid
How does food move down the Oesophagus?
Peristalis
What is the function of bile?
- emulsifies fats
- neutralises stomach acid
What is an enzyme?
A biological catalyst
Why are enzymes described as ‘specific’?
Because they are complimentary to 1 substrate.
Describe how enzymes work: [6 points]
- The enzyme and substrate collide
- Substrate binds to the active site of the enzyme
- Active site is specific// complementary to one type of substrate –> Allows the reaction to occur.
- Binding the active site strains the chemical bonds in the substrate molecules, and so the reaction occurs by an alternative pathway with a lower activation energy (the energy needed for the reaction to occur).
- Once the reaction has occurred, the products do not fit the active site’s shape as well, so they are released.
- After the reaction the enzyme molecule is free to catalyse the next reaction
What is energy measured in?
Kilojoules
Describe how you would measure the energy content of a banana chip: [7 points + equation]
- measure 25 cm3 of water into a boiling tube
- measure mass of food
- measre starting temperature of food
- set light to food suing bunsen burner and hold under boiling tube of wate runtil it goes out
- relight and repeat until it won’t catch fire.
- meauser finishing temperature of water
- calculate temperature change >
Energy content = (volume of water* temperature change *4.2)/mass of food
Where is hydrchloric acid produced?
Stomach
What is the role of the mouth?
Digestion of food starts in the mouth. Teeth break down the food and mix it with the enzymes in saliva.
What is the role of the salivary gland?
Helps digest the starches in food (releases saliva into your mouth and releases amalase, which breaks the stach down into maltose.)
What is the role of the oesophagus?
Thin tube that connects the mouth to the stomach
What is the role of the small intestine? [2 points]
Here, carbohydrates, proteins and lipids digest. The nutrients produced are then absorbed into the blood.
Whtat is the role of the large intestine?
Food that cannot be taken down (mostly fibre) is passes through. Water absorbed into the blood from here.
What is the role of the pancreas?
Releases enzymes which break down carbohydrates, proteins and lipids.
What is the role of the liver?
Releases a chemical called bile into the intestines. Bile breaks down lipids in the food.
What is the role of the gall bladder?
Stores bile.