Biological Molecules: Monomers, Polymers, and Reactions for GCSE Biology

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 (which are 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.

Give examples of monomers.

Monosaccharides, amino acids, nucleotides

What reaction joins two monomers together?

Condensation reaction

What reaction breaks down polymers?

Hydrolysis reaction

What type of chemical bond is formed between monomers?

Covalent bond

Why is it known as a condensation reaction?

Because a molecule of water is produced when two monomers are joined.

Describe the process of hydrolysis.

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

What type of polymer is made from monosaccharides and what bond joins them together?

Polysaccharides joined by glycosidic bonds.

What type of polymer is made from amino acids and what bond joins them together?

Proteins joined by peptide bonds.

What type of polymer is made from nucleotides and what bond joins them together?

Nucleic acids joined by phosphodiester bonds.

What elements are common to all the molecules of life?

Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

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?

Lipids.

Which biological molecules are required to make proteins?

Amino acids.

What are respiratory substrates?

Molecules that provide energy for cells.

What is the role of carbohydrates in cells?

Provide energy and structural support.

What is the role of lipids in cells?

Energy storage and forming cell membranes.

What is the role of proteins in cells?

Building cellular structures and functioning as enzymes.

What is the role of nucleic acids in cells?

Storing and transmitting genetic information.

What is an amino acid?

A monomer which makes up proteins.

What is a condensation reaction?

A chemical process in which two molecules combine to form a more complex one with the elimination of a simple substance, usually water.

What is a covalent bond?

A type of chemical bond in which two atoms share a pair of electrons.

What is hydrolysis?

The breaking down of large molecules into smaller ones by the addition of water molecules.

What is a monosaccharide?

A single sugar, e.g., glucose, which is a monomer of long chain carbohydrate polymers.

What is a nucleotide?

A compound consisting of an organic base and ribose sugar linked to a phosphate group; forms monomers of nucleic acids such as DNA.

What is an organic molecule?

Molecules containing carbon that can be found in living things; four classes are carbohydrates, proteins, lipids, and nucleic acids.

What type of chemical bond is formed between monomers in carbohydrates?

Glycosidic bond.

What type of polymer is made from amino acids?

Polypeptide.

What type of bond joins amino acids together?

Peptide bond.

What type of polymer is made from nucleotides?

Polynucleotide.

What type of bond joins nucleotides together?

Phosphodiester bond.

What are examples of carbohydrates?

Glycogen, cellulose, starch.

What are examples of proteins?

Enzymes, antibodies, channel proteins, hemoglobin.

What are examples of nucleic acids?

DNA and RNA.