Y3 Bio Topic 3 Flashcards
What are the four main classes of macromolecules in living organisms?
Carbohydrates, lipids (fats), proteins, and nucleic acids.
Which chemical elements make up carbohydrates?
Carbon (C), Hydrogen (H), and Oxygen (O), with a H:O ratio of 2:1.
Which chemical elements make up fats?
Carbon (C), Hydrogen (H), and Oxygen (O), but the H:O ratio is not 2:1.
Which chemical elements make up proteins?
Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), and sometimes Sulfur (S).
Which chemical elements make up nucleic acids?
Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), and Phosphorus (P).
What are the three types of carbohydrates?
Monosaccharides (single sugars), disaccharides (double sugars), and polysaccharides (complex carbohydrates).
What is the general formula for carbohydrates?
CnH2mOm
Give an example of a monosaccharide.
Glucose (C6H12O6) or fructose (C6H12O6).
What is the function of glucose in living organisms?
Glucose is the main substrate for cellular respiration, releasing energy for cells.
What is an example of a disaccharide and how is it formed?
Sucrose (table sugar) is formed by joining glucose and fructose.
What is an example of a polysaccharide used for energy storage in plants?
Starch.
What is an example of a polysaccharide used for energy storage in animals?
Glycogen.
What is the structural polysaccharide found in plant cell walls?
Cellulose.
What is the structural polysaccharide found in fungi and exoskeletons of arthropods?
Chitin.
What are the functions of carbohydrates in living organisms?
Immediate energy source (glucose), storage (starch in plants, glycogen in animals), structural support (cellulose in plants), and synthesis of nucleic acids.
What are the two components of a fat molecule?
Glycerol and fatty acids.
How are triglycerides formed?
By the condensation of one glycerol molecule and three fatty acid molecules.
What is the difference between saturated and unsaturated fatty acids?
Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.
Which type of fat is solid at room temperature?
Saturated fat (e.g. animal fat).
Which type of fat is liquid at room temperature?
Unsaturated fat (e.g. plant and fish oils).
Why are unsaturated fats liquid at room temperature?
The kinks in the fatty acid chains prevent tight packing, making them more fluid.
What are the functions of fats in living organisms?
Long-term energy storage, insulation, protection of organs, structural components (cell membranes), and hormone production.
What is the primary structural component of cell membranes?
Phospholipids.
What is cholesterol and why is it important?
Cholesterol is a type of steroid important for maintaining membrane fluidity and synthesizing certain hormones.
What is the basic unit of a protein?
Amino acids.
How many different amino acids are found in proteins?
20.
What type of bond forms between amino acids?
Peptide bond.
What are the functions of proteins?
Growth and repair, enzyme production, hormone synthesis, immune defense (antibodies), structural support (keratin, collagen), and transport (hemoglobin).
What is an enzyme?
A biological catalyst that speeds up chemical reactions in living organisms.
What is hemoglobin?
A protein in red blood cells that transports oxygen.
What are antibodies?
Proteins that help defend the body against pathogens.
What are nucleic acids?
Macromolecules that store and transmit genetic information.
What are the two types of nucleic acids?
Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
What are the three components of a nucleotide?
A phosphate group, a pentose sugar, and a nitrogenous base.
What is the function of DNA?
Stores genetic information and instructions for protein synthesis.
What is the function of RNA?
Assists in protein synthesis by carrying genetic instructions from DNA to ribosomes.
What is the iodine test used for?
Detecting starch.
How is the iodine test performed?
Add iodine solution to a sample; a color change to blue-black indicates the presence of starch.
What is the Benedict’s test used for?
Detecting reducing sugars (e.g., glucose, maltose).
How is the Benedict’s test performed?
Add Benedict’s solution to a sample and heat in a boiling water bath; a color change to green, yellow, orange, or brick-red indicates the presence of reducing sugars.
What is the Biuret test used for?
Detecting proteins.
How is the Biuret test performed?
Add sodium hydroxide and copper sulfate solution; a purple or violet color indicates the presence of proteins.
What is the ethanol emulsion test used for?
Detecting fats (lipids).
How is the ethanol emulsion test performed?
Mix the sample with ethanol, then add water; the appearance of a white emulsion indicates the presence of fats.
What is the importance of food tests?
They help identify the presence of specific nutrients in food samples.
What is the difference between hydrolysis and condensation reactions?
Hydrolysis breaks down macromolecules by adding water, while condensation builds macromolecules by removing water.
How are starch, glycogen, and cellulose formed?
They are all polysaccharides made from glucose monomers.
How are proteins synthesized?
Proteins are synthesized by linking amino acids together in a specific sequence via peptide bonds.
How are fats synthesized?
Fats are synthesized from glycerol and fatty acids through ester bonds.
What is the main function of nucleic acids?
Storing and transmitting genetic information.
What is an example of a storage protein?
Ovalbumin (egg white protein) or casein (milk protein).
What is an example of a structural protein?
Collagen or keratin.
What is an example of a transport protein?
Hemoglobin, which carries oxygen in the blood.
What is an example of a hormonal protein?
Insulin, which regulates blood sugar levels.
Why are macromolecules important in living organisms?
They are essential for energy storage, structure, genetic information, and biochemical functions in cells.
