biological molecules (bio) Flashcards
What are biological molecules?
Molecules of life, critically important for organisms to survive.
They are 3D structures that contain carbon atoms.
What are the main types of biological molecules?
Carbohydrates, lipids, and proteins.
All are classified as macromolecules.
What are polymers?
Macromolecules built from repeating monomers (basic units).
What is the general formula for carbohydrates?
Cm(H2O)n, where hydrogen and oxygen atoms are present in a 2:1 ratio.
What are monosaccharides?
The simplest form of carbohydrates, with common examples being glucose, galactose, and fructose.
They share the same general formula but are arranged differently, leading to different properties.
What are common properties of monosaccharides?
Sweet tasting, soluble in water, and able to lower water potential.
What are disaccharides?
Carbohydrates formed by the bond called a glycosidic bond (covalent bond).
Common types include maltose, sucrose, and lactose.
What is maltose?
A disaccharide made of glucose and glucose, occurring in malted cereals and sprouting grains.
What is lactose?
A disaccharide made of glucose and galactose, found in milk.
What is sucrose?
A disaccharide made of glucose and fructose, found in sugarcane stems, sweet fruits, and storage roots.
What are polysaccharides?
Carbohydrates that include storage polysaccharides (like starch and glycogen) and structural polysaccharides (like cellulose).
What is starch?
A storage polysaccharide in plants, formed by the condensation of a large number of glucose molecules, and is insoluble in water.
What is glycogen?
A storage polysaccharide mainly found in animals, consisting of highly branched chains of glucose molecules and is insoluble in water.
Why are starch and glycogen suitable storage materials?
They are insoluble in water, too large to diffuse through cell membranes, occupy less space than individual glucose, and can be easily broken down into glucose when needed.
What is cellulose?
A structural polysaccharide made from glucose, bonded differently than starch, and is insoluble in water, forming the cell wall in plants.
What are the general functions of carbohydrates?
Glucose serves as a substrate for respiration, releasing energy for cell activities, while deoxyribose/ribose sugars are involved in nucleic acid formation.
What are lipids?
Biological molecules made of carbon, hydrogen, and oxygen, with much less oxygen than hydrogen and carbon, and are insoluble in water but soluble in organic solvents.
What are simple lipids?
Triglycerides formed by linking three molecules of fatty acids and one molecule of glycerol through condensation reactions, creating ester bonds.
What are the properties of fats and oils?
Fats are solid (saturated) and oils are liquid (unsaturated), with oils having at least one carbon-carbon double bond and lower melting points and molecular weight
What are the main functions of lipids?
Energy storage, insulation, buoyancy, protection, and providing metabolic water, allow rapid transmission of electrical impulses, solvent
What are compound lipids?
Phospholipids consisting of two molecules of fatty acids, one molecule of glycerol, and a phosphate group, forming a major component of membranes.
What are proteins?
Biological molecules made of carbon, hydrogen, oxygen, and nitrogen, with a unique 3D shape that can be denatured when heated.
What are amino acids?
Monomers of proteins, each containing a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable group [R].
What is the formation of polypeptides?
Amino acids are joined in a chain through peptide bonds formed by the reaction of the amino group with the carboxyl group of another amino acid.
