Slide 1

Biomolecules

Biomolecules are the organic compounds present in living organisms.
They are essential for life processes and constitute the building blocks of cells and tissues.
Biomolecules include carbohydrates, lipids, proteins, and nucleic acids.

Slide 2

Carbohydrates

Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen in a ratio of 1:2:1.
They are classified into monosaccharides, disaccharides, and polysaccharides.
Examples of monosaccharides include glucose, fructose, and galactose.

Slide 3

Carbohydrates (contd.)

Disaccharides are formed by the condensation of two monosaccharide units.
Sucrose (glucose + fructose) and lactose (glucose + galactose) are examples of disaccharides.
Polysaccharides are complex carbohydrates made up of many monosaccharide units.
Starch and cellulose are examples of polysaccharides.

Slide 4

Lipids

Lipids are hydrophobic organic compounds that include fats, oils, and waxes.
They are composed of glycerol and fatty acids.
Lipids are important for energy storage, insulation, and protection of organs.
Examples of lipids include triglycerides, phospholipids, and cholesterol.

Slide 5

Proteins

Proteins are complex macromolecules composed of amino acids.
They play a vital role in various biological processes such as enzymatic reactions, structural support, and transport.
Proteins are classified into primary, secondary, tertiary, and quaternary structures.
Examples of proteins include enzymes, antibodies, and hemoglobin.

Slide 6

Proteins (contd.)

Amino acids are the building blocks of proteins.
They are composed of an amino group, a carboxyl group, and a side chain.
There are 20 different amino acids, each with a unique side chain.
The sequence of amino acids determines the structure and function of a protein.

Slide 7

Nucleic Acids

Nucleic acids are macromolecules that store and transmit genetic information.
They are composed of nucleotides.
DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are two types of nucleic acids.
DNA contains the genetic instructions for the development and function of living organisms.

Slide 8

DNA Structure

DNA is a double-stranded helical structure.
It consists of nucleotides that are linked through phosphodiester bonds.
The two strands are held together by hydrogen bonds between complementary base pairs.
Adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).

Slide 9

DNA Replication

DNA replication is the process by which DNA is duplicated.
It occurs during cell division to ensure that each daughter cell receives an exact copy of the DNA.
The replication process is semiconservative, meaning that each new DNA molecule consists of one original strand and one newly synthesized strand.

Slide 10

Summary

Biomolecules are essential organic compounds found in living organisms.
Carbohydrates are made up of monosaccharides, disaccharides, and polysaccharides.
Lipids are hydrophobic compounds important for energy storage.
Proteins are composed of amino acids and have various functions.
Nucleic acids store and transmit genetic information.

Slide 11

Carbohydrates (contd.)

Monosaccharides are the simplest form of carbohydrates.
Glucose is the primary source of energy for cells.
Fructose is a monosaccharide found in fruits and honey.
Galactose is a component of lactose, the sugar found in milk.

Slide 12

Carbohydrates (contd.)

Disaccharides are formed by the condensation of two monosaccharide units.
Lactose is found in milk and is composed of glucose and galactose.
Maltose is formed during the digestion of starch and consists of two glucose units.
Sucrose, or table sugar, is composed of glucose and fructose.

Slide 13

Carbohydrates (contd.)

Polysaccharides are long chains of monosaccharides.
Starch is a storage polysaccharide in plants, composed of glucose units.
Glycogen is a storage polysaccharide in animals, stored in the liver and muscles.
Cellulose is a structural polysaccharide found in the cell walls of plants.

Slide 14

Lipids (contd.)

Triglycerides are the most common type of lipid.
They are composed of glycerol and three fatty acid chains.
Fats are solid at room temperature, while oils are liquid.
Saturated fats have single bonds between carbon atoms, while unsaturated fats have double bonds.

Slide 15

Lipids (contd.)

Phospholipids are a major component of cell membranes.
They have a hydrophilic head and hydrophobic tails.
Cholesterol is a type of lipid found in cell membranes.
It plays a role in maintaining membrane fluidity and serves as a precursor for steroid hormones.

Slide 16

Proteins (contd.)

A protein’s structure determines its function.
Primary structure is the linear sequence of amino acids.
Secondary structure refers to the folding of the protein into alpha helices or beta sheets.
Tertiary structure is the 3D arrangement of the protein.

Slide 17

Proteins (contd.)

Quaternary structure refers to the combination of multiple protein subunits.
Enzymes are proteins that catalyze biochemical reactions.
Antibodies are proteins that help to fight infections.
Hemoglobin is a protein that carries oxygen in the blood.

Slide 18

Nucleic Acids (contd.)

RNA is involved in protein synthesis.
It carries the genetic information from DNA to the ribosomes.
RNA is composed of ribose sugar, phosphate group, and nitrogenous bases (adenine, guanine, cytosine, and uracil).
There are three types of RNA: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).

Slide 19

DNA Structure (contd.)

The double helix structure of DNA was discovered by Watson and Crick.
The two DNA strands are antiparallel, running in opposite directions.
The sugar-phosphate backbone forms the outside of the helix.
The base pairs are held together by hydrogen bonds.

Slide 20

DNA Replication (contd.)

DNA replication occurs in three main stages: initiation, elongation, and termination.
During initiation, DNA helicase unwinds the double helix and creates a replication fork.
DNA polymerase adds nucleotides to the growing DNA strand during elongation.
The process is bidirectional, occurring in both directions from the replication fork.

Slide 21

DNA Replication (contd.)

The leading strand is synthesized continuously in the 5’ to 3’ direction.
The lagging strand is synthesized discontinuously in small fragments called Okazaki fragments.
DNA ligase joins the Okazaki fragments together.
The proofreading activity of DNA polymerase helps to ensure accuracy during replication.

Slide 22

Transcription

Transcription is the process by which RNA is synthesized from a DNA template.
It occurs in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells.
RNA polymerase binds to the DNA and separates the strands.
The RNA polymerase adds complementary RNA nucleotides to form an RNA molecule.

Slide 23

Translation

Translation is the process by which the genetic information in mRNA is used to synthesize proteins.
It occurs in the ribosomes.
Transfer RNA (tRNA) carries amino acids to the ribosomes.
The ribosome reads the codons on the mRNA and brings in the corresponding tRNA with the correct amino acid.

Slide 24

Protein Structure (contd.)

Quaternary structure refers to the combination of multiple protein subunits.
Proteins can have multiple subunits that come together to form a functional protein.
Hemoglobin, for example, consists of four subunits.
The quaternary structure is stabilized by various interactions, including hydrogen bonds and disulfide bridges.

Slide 25

Denaturation of Proteins

Denaturation is the process by which proteins lose their structural conformation.
This can occur due to changes in temperature, pH, or exposure to chemicals.
Denaturation leads to a loss of protein function.
Examples of denatured proteins include cooked egg white and curdled milk.

Slide 26

Enzymes

Enzymes are biological catalysts that speed up chemical reactions.
They lower the activation energy required for a reaction to occur.
Enzymes are specific for a particular substrate and bind to it at the active site.
Examples of enzymes include amylase, lipase, and catalase.

Slide 27

Enzyme Regulation

Enzyme activity can be regulated to ensure proper cellular function.
Regulation can occur through feedback inhibition, where the end product of a metabolic pathway inhibits an earlier step.
Enzyme activity can also be regulated by allosteric regulation, where a molecule binds to a site other than the active site and affects the enzyme’s activity.

Slide 28

Energy Changes in Chemical Reactions

Chemical reactions involve a transfer of energy.
Exothermic reactions release energy in the form of heat.
Endothermic reactions absorb energy from the surroundings.
The overall energy change in a reaction is determined by the difference between the energy of the reactants and the energy of the products.

Slide 29

Chemical Equilibrium

Chemical equilibrium is a state in which the forward and reverse reactions occur at equal rates.
The concentration of reactants and products remains constant at equilibrium.
The equilibrium constant (Kc) is used to express the ratio of products to reactants at equilibrium.
Le Chatelier’s principle predicts the shift in equilibrium when conditions such as temperature or pressure are changed.

Slide 30

Redox Reactions

Redox (reduction-oxidation) reactions involve the transfer of electrons between reactants.
Oxidation refers to the loss of electrons, while reduction refers to the gain of electrons.
Redox reactions are essential for energy production in living organisms.
Examples of redox reactions include combustion and cellular respiration.