1.1 - Introduction To Biological Molecules Flashcards
What is the role of carbohydrates in living organisms?
- Carbohydrates serve as respiratory substrates from which cells release energy required for their functions.
- They also have structural roles in cell walls and form part of glycoproteins and glycolipids, which act as recognition sites in plasma membranes.
Name two major roles of lipids in biological systems
- Lipids form a major component of plasma membranes and act as respiratory substrates.
- They also make up certain hormones.
What is the significance of proteins in biological systems?
- Proteins have a diverse range of structures and functions.
- They are found in plasma membranes, act as enzymes, serve as chemical messengers within and between cells, and are important components of the blood, such as antibodies.
What is the primary function of DNA and RNA in living organisms?
DNA carries genetic information that determines the structure of proteins, while RNA plays a role in the synthesis of these proteins.
What are biological molecules, and what is their study called?
Biological molecules are specific groups of chemicals found in living organisms. Their study is called molecular biology.
Describe covalent bonding.
Covalent bonding occurs when atoms share a pair of electrons in their outer shells, resulting in a more stable compound called a molecule.
What is ionic bonding?
Ionic bonding is the electrostatic attraction between ions with opposite charges, such as sodium ions (Na⁺) and chloride ions (Cl⁻) forming sodium chloride. It is weaker than covalent bonding
Explain hydrogen bonding and its importance.
Hydrogen bonding occurs when regions of polar molecules with uneven electron distribution attract each other. These weak electrostatic bonds collectively alter the physical properties of molecules, such as water.
Define monomers, polymers, and polymerisation.
- Monomers are individual units that link to form long chains called polymers.
- The process of forming polymers is known as polymerisation.
Give examples of biological polymers and their monomers.
- Polysaccharides are formed from monosaccharides (e.g., glucose).
- Polypeptides are formed from peptides with amino acids as their basic subunits.
- Polynucleotides are formed from mononucleotide subunits
What is a condensation reaction? Provide an example.
A condensation reaction occurs during polymerisation when a molecule of water is released as a new subunit is added. For example, the formation of starch from glucose is a condensation reaction.
What is a hydrolysis reaction? Provide an example.
A hydrolysis reaction involves breaking the bonds in a polymer by adding water, splitting it into its subunits. For example, starch can be hydrolysed into glucose.
Define metabolism.
Metabolism refers to all the chemical processes that occur within living organisms.
What is the mole, and what does it measure?
The mole (mol) is the SI unit for measuring the amount of a substance. One mole contains 6.022 × 10²³ particles, known as the Avogadro constant.
How do you prepare a 1 M solution of sodium chloride?
Calculate the molecular mass of NaCl: 23 (Na) + 35.5 (Cl) = 58.5 g. Dissolve 58.5 grams of sodium chloride in 1 litre of solution to make a 1 M solution.
