Bio topics 3 and 4 Flashcards
What basic unit forms Carbohydrate molecules?
Simple sugars - Carbon, Hydrogen and Oxygen.
Give an example of a simple sugar.
Glucose, Sucrose, Maltose, Galactose, Lactose, Fructose
What larger molecules can simple sugar molecules form?
Sucrose (pair)
Starch, Glycogen and Cellulose (chain)
What forms proteins?
Amino acids - Carbon, Hydrogen, Nitrogen and Oxygen.
What simple unit makes up Lipids?
Fatty acids and Glycerol
What is the function of protein?
Growth and repair
Make up Enzymes
Why are Lipids important to the body?
They form cell membranes + other molecules in the body such as fats in storage cells.
Describe the test for starch.
Drop iodine solution in substance
If starch is present, the colour changes from brown to dark blue.
Describe the test for Glucose (reducing sugar).
Add Benedict's solution to the sample Heat up in water bath If reducing sugar is present, colour will change from blue to: Green - small amount Yellow - medium amount orange - large amount
Describe the test for proteins.
Add biuret solution to the sample
If protein is present colour will turn from blue to purple.
Describe the test for fat.
Add ethanol in sample and shake
If fat is present, it will dissolve in ethanol to from a cloudy solution.
What is an enzyme?
An enzyme is a biological catalyst made from proteins
What is a catalyst?
A catalyst is a substance that changes the speed of a chemical reaction without being used up in the process.
What are metabolic reactions?
Chemical reactions in the body’s cells that convert food to energy.
What is a substrate?
A molecule which an enzyme joins with at the start of a reaction.
What is a product?
A molecule formed at the end of a reaction.
Describe enzyme action.
Enzymes have an active site
Active site shape is complementary to substrate’s shape. (Substrate fits into active site)
Substrate splits into two product molecules released from the enzyme.
What is an enzyme-substrate complex.
A molecule formed when an enzyme and substrate join together.
What enzyme breaks down carbohydrates?
Amylase - produced in the mouth.
What enzyme breaks down proteins?
Protease - produced in stomach.
What enzyme breaks down Lipids?
Lipase - produced in small intestine.
What is meant by optimum temperature?
The temperature which enzymes work best at
Humans - around 37 degrees (body temp)
What happens when the temp goes over the optimum?
Denatured.
The shape of the active site will change - no reaction.
Temp increase will result in…
More kinetic energy, particles move faster, more successful collisions between enzyme and substrate.
What is meant by optimum pH?
The pH which enzymes work best at.
Each enzyme has a different optimum pH.
Describe the effect of pH on the enzyme.
Shape of enzyme depends on pH.
Shape of active site will change if pH changes too much.
