Bio chemestry test reveiw

Organic Molecules

• Definition: Molecules that contain carbon.
• Significance: Fundamental to all living organisms, as carbon-containing compounds are vital for life.
• Carbon's Versatility: A carbon atom can form millions of different combinations with other atoms due to its bonding versatility.

Inorganic Molecules

• Definition: Molecules that do not contain carbon.
• Most Important Inorganic Molecule: Water, essential for living organisms.

Biomolecules

• Categories:
  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic Acids

Carbohydrates

• Definition: Sugars that serve as an energy source.
• Chemical Composition: Composed of:
  • Carbon: 1 atom
  • Hydrogen: 2 atoms
  • Oxygen: 1 atom
• Structure: Comprised of chains of carbon units with attached hydroxyl groups.

Types of Carbohydrates

• Monosaccharides:

  • Definition: Simple sugars.
  • Examples:
  • Glucose: C₆H₁₂O₆
  • Fructose: C₆H₁₂O₆
  • Galactose: C₆H₁₂O₆

• Disaccharides:

  • Definition: Formed by the combination of two monosaccharides (known as isomers due to indifferent arrangement).
  • Examples:
  • Sucrose: Fructose + Glucose
  • Lactose: Galactose + Glucose
  • Maltose: Glucose + Glucose

• Polysaccharides:

  • Definition: Complex sugars consisting of 10 or more monosaccharides.
  • Examples:
  • Cellulose: Tough, indigestible structural material in plant cell walls (fiber).
  • Starch: Easily digestible storage form of glucose in plants.
  • Glycogen: Storage form of glucose in animals, primarily in muscle and liver cells. When blood sugar decreases, liver cells degrade glycogen and release glucose.
  • Chitin: Structural material for exoskeletons of invertebrates and cell walls of fungi.

Functions of Carbohydrates

• Nutritional Role: Provide the body with heat and energy.

Lipids

Definition and Structure

• Definition: Fats that are hydrophobic and do not dissolve in water.
• Structure: Composed of chains of methyl (-CH) units.

Types of Lipids

• Common Fats: Comprises three fatty acids bound to a glycerol backbone.

  • Fatty Acids: Long chains of carbon with hydrogen atoms bonded to them.
  • Glycerol: Composed of 3 carbons.
  • Examples: Butter, meat.

• Phospholipids: Essential components of the lipid bilayer of cell membranes.

• Waxes: Long-chain fatty acids that offer a firm consistency and repel water, acting as waterproofing agents (e.g., beeswax, earwax).

• Saturated Fatty Acids:

  • Characteristics: No double bonds between carbon atoms; solid at room temperature; primarily derived from animal sources (meat, eggs, dairy).
  • Health Impact: Considered unhealthy fats.

• Unsaturated Fatty Acids:

  • Characteristics: One or more double bonds prevent close packing; tend to be liquid at room temperature; primarily found in plants and fish.
  • Examples: Cooking oils, oily fish (e.g., salmon).
  • Health Impact: Considered healthier fats.

Triglycerides

• Definition: Comprise saturated and unsaturated fats, acting as major energy storage.
• Health Risks: High consumption can lead to heart disease due to excess calories being converted to fat.

Steroids

• Function: Used for chemical signaling within the body, influence cell membrane fluidity, and regulate hormones like estrogen and testosterone. They also affect DNA and facilitate cell growth and synthesis of proteins.

Functions of Lipids

• Roles:
  • Insulation and body heat maintenance.
  • Energy storage.
  • Membrane formation, creating protective coverings.
  • Hormone production and vitamin solubility.

Proteins

Definition and Structure

• Composition: Long, linear chains of amino acids.
• Amino Acids: Building blocks of proteins, with 20 different types combining to create every protein in the body.

Elements Present in Proteins

• Composed of:
  • Carbon
  • Hydrogen
  • Oxygen
  • Nitrogen
  • Traces of elements like sulfur.

Protein Production

• Dietary Requirement: Not all amino acids can be synthesized by the body; some must be obtained through diet. Proteins are broken down in the digestive system into amino acids, which are then used to build proteins.
• Peptide Bond: The bond formed between two amino acids.

Protein Structure Levels

1. Primary Structure: Sequence of amino acids unique to each protein (e.g., Glycine, Leucine, Alanine, Lysine).
2. Secondary Structure: Formation of helices and pleated sheets due to interactions between the amino acids.
3. Tertiary Structure: Further folding and bonding interactions that give proteins their three-dimensional shape, essential for function.
4. Quaternary Structure: Proteins comprised of more than one polypeptide chain form complex multi-subunit structures.

Denaturation

• Definition: The alteration of a protein's three-dimensional shape, which breaks bonds and disrupts function.
• Causes:
  • pH changes
  • Temperature changes
• Consequences: Denaturation prevents proteins from functioning properly.

Functions

• Biological Role:
  • Growth of new cells.
  • Repair of damaged cells.
  • Production of heat and energy.
  • Manufacture of enzymes, hormones, and antibodies.
• Consequences of Protein Deficiency: Slow growth in children, inability to replace worn-out cells, impaired wound healing, increased susceptibility to diseases due to lack of antibodies.

Nucleic Acids

Definition

• Description: Molecules that serve as the backbone of genetic material, including DNA and RNA.

Composition

• Elements: Made up of C, H, O, N, P (phosphorus).
• Nucleotides: Building blocks composed of:
  • Sugars
  • Phosphate groups
  • Nitrogenous bases

Functions of Nucleotides

• Roles:
  • Carrier of energy
  • Coenzymes and chemical messengers
  • Building blocks for nucleic acids.

Types of Nucleic Acids

• DNA (Deoxyribonucleic Acid):

  • Structure: Comprises two strands of nucleotides.
  • Sugar: Deoxyribose.
  • Function: Controls cell activities and stores hereditary information.

• RNA (Ribonucleic Acid):

  • Structure: Single strand of nucleotides.
  • Sugar: Ribose.
  • Function: Involved in protein synthesis.