bio - enzymes, food tests and organisation Flashcards
Cell
What all living things are made from
Tissue
Cells working together to perform a certain function
Organ
Tissues working together to perform a function
Organ system
Organs working together to perform a function
Organism
Organ systems working together. Plant/animal
What are carbohydrates?
Simple sugars (glucose) and starch (chains of simple sugars)
What are proteins?
Amino acids
What are lipids?
Fatty acids and glycerol
Test for sugars
Benedict’s solution, blue to brick red, requires heat
Test for starch
Iodine, orange to blue/black
Test for protein
Biuret solution, blue to purple
Test for lipids
Ethanol, clear to milky white
What is the digestive system?
An organ system in which organs work together to digest and absorb food
Enzyme
A large protein that acts as a biological catalyst, speeding up the rate of a reaction
Metabolism
The sum of all the reactions in a cell or body
Active site
The specific shape that allows the enzyme to bind to it’s substrate
Explain the lock and key model
Enzymes only bind to one specific substrate and won’t catalyse one if it doesn’t fit.
Denatured
When the active site no longer fits the substrate
How does temperature affect enzymes?
Increasing the temperature increases the rate of the enzyme’s reaction. Until it gets too hot and the bonds of the enzyme break
Optimum temperature
The temperature at which enzymes work best. This can change for different enzymes
What does pH do to enzymes?
Denature the enzyme
How do you investigate the effects of pH on the rate of breakdown of starch by amylase?
Using a continuous sampling technique to find the time to completely digest starch solution. Use iodine.
Equation to calculate the rate of an enzyme controlled reaction
1/time in seconds
Why are large food molecules broken down?
They can’t be absorbed into the bloodstream
What are the products of digestion used for?
Making new carbohydrates, proteins and lipids and glucose is used for energy release
What do carbohydrases do?
Break down carbohydrates into simple sugars
Where are carbohydrases found?
Salivary glands, pancreas, small intestine (amylase)
