Unit 1 Biology- Question and Answer

What is the role of cohesion in water?

Cohesion allows water molecules to stick together, contributing to high surface tension.

What is the main function of water as a solvent?

Water is a medium for metabolic reactions and dissolves polar molecules and ionic compounds.

What is the difference between hydrophilic and hydrophobic substances?

Hydrophilic substances attract water, while hydrophobic substances repel water.

What defines buoyancy in an object?

Buoyancy is the ability to float, determined by the upward force equal to the weight of the fluid displaced.

What type of acid are all living organisms composed of?

DNA (Deoxyribonucleic Acid)

What are the components of a nucleotide?

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

What is the difference between DNA and RNA in terms of structure?

DNA (Deoxyribonucleic Acid) is structured as a double helix composed of two long strands of nucleotides that coil around each other, providing stability and protection for genetic information. It is typically longer and contains the genetic blueprint for the organism. In contrast, RNA (Ribonucleic Acid) is usually a single-stranded molecule and shorter than DNA, consisting of a single chain of nucleotides. RNA plays various roles in protein synthesis and gene regulation, and its structure allows for flexibility and functionality in different biological processes.

What is a peptide bond?

A peptide bond is formed between two amino acids during condensation reactions.

What are the four levels of protein structure? Describe them.

The four levels of protein structure are: 1) Primary structure - the unique sequence of amino acids in a polypeptide chain 2) Secondary structure - the local folded structures that form within a polypeptide due to hydrogen bonding, commonly seen as alpha helices and beta-pleated sheets. 3) Tertiary structure - the three-dimensional shape of a protein that results from the interactions and folding of the secondary structures, contributing to the overall stability and function of the protein. 4) Quaternary structure - the arrangement and interaction of multiple polypeptide chains or subunits to form a functional protein complex, often involving non-covalent interactions.

What type of reactions are involved in metabolism?

Catabolism (breakdown) and anabolism (building).

What are monosaccharides?

Monosaccharides are the simplest form of carbohydrates, consisting of single sugar molecules that cannot be hydrolyzed into smaller carbohydrate units. They serve as basic building blocks for more complex carbohydrates and are characterized by their general formula (CnH2nOn), where 'n' typically ranges from 3 to 7. Common examples include glucose, which is crucial for energy metabolism; fructose, found in many fruits; and ribose, an essential sugar in the structure of RNA.

What is the role of triglycerides in the body?

Triglycerides serve as energy storage and can be hydrolyzed for energy.

What are enzymes?

Enzymes are biological catalysts that speed up biochemical reactions by lowering activation energy.

What is the purpose of allosteric regulation in enzymes?

Allosteric regulation allows control of enzyme activity and substrate interactions.

What happens in competitive inhibition of enzymes?

In competitive inhibition, an inhibitor binds to the active site, slowing down the enzyme's action.

How do high density lipoproteins (HDL) function in the body?

HDL scavenges excess cholesterol from the body, helping remove it through the digestive tract.