3.19 Biological Molecules Flashcards
What are biological molecules produced by?
Cells
What are nutrients?
Substances that are needed for growth, repair and metabolism.
What are carbohydrates?
Molecules made from atoms of carbon, hydrogen, and oxygen.
Describe how carbohydrates can come in different sizes
Carbohydrates come in different sizes. with the smallest carbohydrates being simple sugars, such as glucose and fructose. We call these simple sugars “monomers”. Carbohydrate monomers can join together to form carbohydrate polymers, such as glycogen and starch.
Chemical bonds in a complex carbohydrate
In a complex carbohydrate, there are chemical bonds between the monomers. If these chemical bonds are broke, the complex carbohydrate can be broken down into simple carbohydrates (e.g. starch can be broken down into glucose molecules).
What are long-chain carbohydrates made from?
Glucose and other sugars.
What breaks down complex carbohydrates in the human body?
Enzymes in the mouth and small intestine
Which three elements are found in carbohydrates?
- Hydrogen
- Oxygen
- Carbon
Is glucose a monomer or a polymer?
Monomer
What are proteins made from?
Amino acids
Is glycogen a monomer or a polymer?
Polymer
Proteins
Proteins are made up of long chains of amino acids bonded together. A protein is a polymer, whilst the amino acids it is made from are the monomers.
What are amino acids made from?
Mainly from carbon, hydrogen, oxygen and nitrogen atoms.
What breaks down proteins in the human body?
Enzymes in the stomach and small intestine.
Lipids
The term “lipids” refers to both fats and oils. A fat is a lipid that’s solid at room temperature, whilst an oil is a lipid that’s liquid at room temperature. Lipids contain a single glycerol molecule attached to three fatty acid molecules.
What determines whether a lipid is a fat or an oil?
The length and structure of the fatty acid molecules.
What three elements are lipids made from?
- Carbon
- Hydrogen
- Oxygen
Are lipids monomers or polymers?
Monomers
What breaks down lipids in the body?
Small intestine
How do plants build up organic molecules in their biomass? (7)
- Producers take in the elements they need to survive from their environment e.g. plants take in carbon from the air and nitrogen compounds from the soil.
- Producers use carbon (along with oxygen and hydrogen) to make glucose during photosynthesis.
- Glucose is then used to make other small organic molecules, e.g. other sugars, fatty acids and glycerol.
- Glucose and nitrate ions are combined to make amino acids.
- These small molecules are then used by the producer to create long-chain carbohydrates, lipids and proteins.
- These larger molecules are used to build structures like cell membranes and organelles.
- All these synthesis reactions are catalysed by enzymes.
How do consumers get organic molecules?
Unlike plants, consumers can only get carbon and nitrogen compounds by eating and digesting the large organic molecules in producers or other consumers in the food chain.
How do consumers digest organic molecules?
Digestion breaks large molecules down into smaller ones, which can be more easily absorbed by the consumer. Proteins are broken down into amino acids, starch is broken down into simple sugars, and lipids are broken down into fatty acids and glycerol. Digestion reactions are also catalysed by enzymes. The small molecules are then transported to the consumers’ cells (usually in the blood supply) to be built up into larger molecules (proteins, etc.) again. These form the biomass of the consumer.
