AQA A-Level Biology 3.1.1: Biological Molecules, Monomers and Polymers

What is the chemical formula for glucose?

C6H12O6

Name 5 things plants and animals need glucose for.

Respiration; storage as starch (plants); storage as glycogen (animals); combined with nitrates to synthesise proteins (plants); stored as lipids (animals)

How do animals get glucose?

Digestion of food molecules

How do plants get glucose?

Photosynthesis

Name 5 uses of proteins in the human body.

Enzymes, growth and repair, hormones, blood clotting, antibodies

Which carbohydrate is found in plant cell walls?

Cellulose

Where in the human body is starch broken down?

Mouth and small intestine

What do proteases do?

Digest proteins

What is the function of an emulsifier?

Break down fats and increase their surface area to allow lipase to work more efficiently

Where are the instructions for making proteins?

Amino acid sequences (coded for by genes)

Name 2 types of chemical bonds.

Ionic; covalent

What is a monomer?

The smaller units from which larger molecules are made.

What is a polymer?

Molecules made from lots of repeating monomers joined together.

What are examples of monomers?

Monosaccharides, amino acids, nucleotides

What type of bond is formed between monosaccharides?

Glycosidic bond

What type of bond is formed between amino acids?

Peptide bond

What type of bond is formed between nucleotides?

Phosphodiester bond

What is a condensation reaction?

A reaction that joins two monomers together with the formation of a covalent bond and involves the elimination of a molecule of water.

What is a hydrolysis reaction?

A reaction that breaks the covalent bond between two monomers and involves the use of a water molecule.

What elements are common to all the molecules of life?

Carbon, Oxygen, Hydrogen

What are the four main groups of carbon-based molecules common to all life forms?

Carbohydrates, Lipids, Proteins, Nucleic Acids

Which molecule forms part of the plasma membrane?

Phospholipids

Which biological molecules are required to make proteins?

Amino acids (and nucleic acids)

Which two biological molecules are the main respiratory substrates?

Lipids and Carbohydrates

Why is it known as a condensation reaction?

A molecule of water is produced/released.

Describe the process of hydrolysis.

A water molecule is used to break a covalent bond. An H and an OH group are joined to the monomers.

What is the main component of many cellular structures?

Proteins

What are nucleic acids?

Polymers (DNA and RNA) that make up the genetic material of organisms.

What is the role of lipids in cells?

Used as respiratory substrates and form a bilayer in cell membranes.

What is the role of carbohydrates in cells?

Provide energy for cells and are used for structure in cell membranes and walls in plants.

What is the main function of proteins in the human body?

Form enzymes and chemical messengers.

What is the significance of the similarities in biological molecules across organisms?

They support the theory that all animals and plants share a common ancestor.

What are organic molecules?

Molecules containing carbon that can be found in living things.

What are the four main classes of organic molecules?

Carbohydrates, proteins, lipids, and nucleic acids.

What is the function of carbohydrates?

Provide energy for cells and structure in cell membranes and walls in plants.

What is the function of lipids?

Provide energy for cells, form a bilayer in cell membranes, and make up some hormones.

What is the function of proteins?

Main component of many cellular structures, form enzymes and chemical messengers.

What is the function of nucleic acids?

Form polymers (DNA and RNA) that make up the genetic material of organisms.

What reaction joins two monomers together?

Condensation reaction.

What reaction breaks down polymers?

Hydrolysis reaction.

What type of polymer is made from monosaccharides?

Polysaccharides.

What type of polymer is made from amino acids?

Polypeptide.

What type of polymer is made from nucleotides?

Polynucleotide.

What is hydrolysis?

A reaction that breaks the covalent bond between two monomers using a water molecule.

What are examples of polysaccharides?

Glycogen, cellulose, and starch.

What are examples of proteins?

Enzymes, antibodies, channel proteins, and hemoglobin.

What is the significance of the similarities in nucleic acids among organisms?

They support the theory that all animals and plants share a common ancestor.

What is the role of water in condensation and hydrolysis reactions?

Water is eliminated in condensation reactions and used to break bonds in hydrolysis reactions.

What is the main respiratory substrate in living organisms?

Carbohydrates and lipids.

What is the main component of cell membranes?

Lipids.

What are the building blocks of proteins?

Amino acids.

What are the building blocks of nucleic acids?

Nucleotides.

What type of bond joins smaller units in carbohydrates?

Glycosidic bonds.

What type of bond joins smaller units in proteins?

Peptide bonds.

What type of bond joins smaller units in nucleic acids?

Phosphodiester bonds.