IB Biology Unit 2: Biochemistry

What is the role of water in life?

Water acts as a liquid medium for chemical reactions necessary for energy, growth, and waste removal.

What chemical elements make up water?

Water is made up of two hydrogen atoms covalently bonded to one oxygen atom.

What is the consequence of polar covalent bonds in water molecules?

They create hydrogen bonds, leading to water's cohesive and adhesive properties.

Define cohesion in the context of water.

Cohesion is the tendency of water molecules to stick to one another due to hydrogen bonding.

What is adhesion in relation to water?

Adhesion is the tendency of water molecules to stick to other charged or polar surfaces.

What is capillary action and why is it important?

Capillary action is the ability of water to move through narrow spaces, essential for plant water transport.

How does water function as a solvent?

Water can dissolve many organic and inorganic substances with charged or polar regions.

What does the term hydrophilic mean?

Hydrophilic substances are chemically attracted to water and dissolve in it.

What does the term hydrophobic mean?

Hydrophobic substances are insoluble in water and do not have charges.

What is the specific heat capacity of water?

Water has a high specific heat capacity, requiring a lot of energy to change temperature.

Why is high boiling point critical for aquatic life?

It allows water to remain liquid over a wide temperature range, supporting life.

How does water cool organisms?

Water absorbs heat gradually, cooling organisms through evaporation and thermal conductivity.

Why is water less dense as a solid?

Hydrogen bonds create an open structure in ice, making it less dense than liquid water.

Describe the primary structure of carbohydrates.

Carbohydrates generally consist of carbon, hydrogen, and oxygen, and can exist as monomers and polymers.

What is a triglyceride?

Triglycerides are lipids composed of glycerol and three fatty acids.

What is the primary role of glycogen in animals?

Glycogen serves as a short-term energy storage molecule found in the liver and muscles.

Identify the main function of cellulose in plants.

Cellulose provides tensile strength and structural support in plant cell walls.

What are glycoproteins?

Glycoproteins are proteins with carbohydrate chains that help in cell-cell recognition.

What are the components of a nucleotide?

A nucleotide consists of a sugar, phosphate group, and a nitrogenous base.

How are DNA and RNA different?

DNA contains deoxyribose sugar and thymine, while RNA contains ribose sugar and uracil.

Explain the significance of complementary base pairing in DNA.

Complementary base pairing ensures accurate replication and transcription of genetic information.

What are the functions of proteins?

Proteins are involved in digestion, transportation, muscle contraction, immune response, and structural support.

What is the role of enzymes?

Enzymes function as catalysts to speed up biochemical reactions without being consumed.

Define denaturation of proteins.

Denaturation is the process where proteins lose their shape and function due to extreme conditions.

What is the role of hemoglobin in blood?

Hemoglobin carries oxygen in red blood cells.

What is the main function of lipids?

Lipids serve as long-term energy storage, structural components of cell membranes, and insulation.

How do triglycerides and phospholipids differ in structure?

Triglycerides consist of one glycerol and three fatty acids, while phospholipids consist of one glycerol, two fatty acids, and a phosphate group.

Why are saturated fatty acids solid at room temperature?

Saturated fatty acids lack double bonds, allowing them to pack tightly and remain solid.

What are enzymes classified as?

Enzymes are classified as proteins that act as biological catalysts.

What is metabolic water?

Metabolic water is produced during biological reactions, vital for hydration.

Why are proteins said to be versatile?

Proteins are versatile due to the variety of amino acids that can combine in different sequences to form diverse structures and functions.

What is the primary structure of an amino acid?

The primary structure consists of an amino group, a carboxyl group, a hydrogen atom, and a unique R group.

What happens during a condensation reaction?

A condensation reaction links monomers to form polymers, releasing water as a byproduct.

Define hydrolysis.

Hydrolysis is a reaction that breaks down polymers into monomers by adding water.

What are essential amino acids?

Essential amino acids are those that must be obtained through diet because the body cannot synthesize them.

What is the role of protein structure levels?

Protein structure levels determine the protein's shape, function, and interactions with other molecules.