Biology: Fundamentals of Chemistry and Life

• Water plays an important role in the maintenance of biological systems.

Functions of Water

• Temperature regulation involving sweat glands producing sweat, cooling the body through evaporation, a process called perspiration.
• Plants are cooled by transpiration, which is the loss of water vapor from their leaves.
• Water is a very important body constituent, providing form and support in plants and animals.
• Animals like worms and jellyfish use water in special chambers in their bodies for support.
• Hydrostatic skeleton refers to the use of water pressure to provide form and enable movement.
• Plants grow upright and remain shaped due to water pressure, called turgor pressure, inside their cells.

Transport Medium

• Transports substances around the body.
• It is a main constituent of blood, enabling blood cells, hormones, dissolved gases, electrolytes, and nutrients to be transported.

Lubricating Agent

• Water is the main constituent of saliva, which aids in chewing, swallowing, and food passage.
• It is also the main component of tears, keeping the eye lubricated.

Solvent for Biological Chemicals

• Water is known as the universal solvent because more substances dissolve in it than any other liquid.
• All chemical reactions in living organisms occur in water.

Reactant

• Takes place in several classes of chemical reactions.
• Water is added to reactions to break down large molecules into smaller ones during hydrolysis.
• Water can be split into hydrogen and oxygen atoms to provide energy for complex chemical reactions like photosynthesis.

Keywords

• Constituent: Being a part of a whole.
• Lubricate: An action to minimize friction and allow smooth movement.

Minerals

• Minerals are chemical elements necessary for living organisms to maintain health.
• Essential minerals include calcium, phosphorus, potassium, sulfur, sodium, chlorine, and magnesium.

Macro-elements / Macro-nutrients

• Nutrients required in large quantities by living organisms.
• Main macro-nutrients: potassium, sodium, calcium, and phosphorus.
• Other elements include carbon, hydrogen, oxygen, nitrogen, chloride, and magnesium. Also sulfur.

Micro-Elements / Micro-nutrients

• Nutirents are required in very small quantities for development and growth.
• Micro-nutrients include iron, iodine, chromium, cobalt, copper, manganese, zinc, and selenium.

Inorganic Fertilizers

• Fertilizers supplement nutrients to soil to help plants and crops grow
• Crops grown and harvested on the same land deplete the soil of nutrients.
• Fertilizers are natural or non-natural substances used to replenish depleted nutrients, improve soil content, and promote plant growth.
• Inorganic nutrients, such as nitrates and phosphates, are added to the soil in the form of inorganic fertilizers.

Effect of Fertilizers on the Environment

• Large amounts of fertilizers can harm the environment.
• Fertilizers washing off into rivers can be poisonous to plant and animal life.
• Accumulation of fertilizers in rivers can lead to eutrophication. Eutrophication is where excess fertilizers leach to land causing high nutrient levels and high growth of water plants.
• Eutrophication leads roots to lose water and plant growth, blocking sunlight, and also underwater plants stop photosynthesizing and die.
• Decomposing plants and bacteria deplete oxygen, causing fish and other animals to suffocate.
• This process reduces oxygen levels, harming aquatic life.

Organic Compounds

• Organic compounds are molecules containing carbon, bonded with hydrogen, and elements like oxygen, nitrogen, and phosphorus.
• Vital for life, exhibiting more complex structures than inorganic compounds.
• Examples include carbohydrates, lipids, proteins, enzymes, vitamins, and nucleic acids (DNA/RNA).

Carbohydrates

• Contain carbon, hydrogen, and oxygen.
• Hydrogen to oxygen ratio is 2:1.
• Building blocks are saccharides (sugars).
• Composition: Made of carbon (C), hydrogen (H), and oxygen (O).
• Carbohydrate refers to carbon and water. The general formula is C(H₂O).

Three Groups of Carbohydrates

• Monosaccharides (single sugars): Glucose, fructose.
• Disaccharides(double sugars): Maltose, sucrose.
• Polysaccharides (many linked sugars): Starch, cellulose, glycogen.
• Source: Monosaccharides and disaccharides found in fruits and vegetables.
• Polysaccharides found in bread, rice, flour, pasta, and potatoes.
• Function: Provides energy for plants and animals.
• Plants store carbohydrates as starch.
• Animals store it as glycogen.
• Cellulose forms cell walls.

Lipids

• Examples include Fats & oils, steroids & cholesterol
• Composed of carbon, hydrogen, and oxygen, with a hydrogen to oxygen ratio greater than 2:1.
• Formed when glycerol combines with three fatty acids.

Types of Fatty Acids

• Saturated fats feature single bonds in the fatty acid chains.
• They exist as solids at room temperature.
• Unsaturated fats include one or more double bonds in the fatty acid chains.
• They exist as liquids at room temperature.
• Animal sources of lipids: butter, fatty meats.
• Plant sources: oils, nuts.
• Can be used as an energy sources providing twice the energy compared to carbohydrates.
• Fats (blubber) prevent heat loss in animals.
• Plants store oils in their seeds.

Lipids: Cholesterol

• Found in the human body and is sourced from both diet and liver production.

Functions:

• Critical component of cell membranes and needed to prduce vitamin D.

Health effects

• Excess cholesterol can deposit on blood vessel walls, leading to atherosclerosis, resulting in the narrowing of blood vessels.
• If a vessel supplying the heart becomes fully blocked it can result in a heart attack.

Types of cholesterol

• HDL (High-Density Lipoprotein): Considered good cholesterol, with beneficial effects on the body.
• LDL (Low-Density Lipoprotein): Considered bad cholesterol, which can be harmful in high amounts.

Risk factors for high cholesterol

• Diet high in saturated fats.
• Obesity.
• Lack of exercise.
• Genetics.
• Aging.
• Fruits and vegetables don't contain cholesterol.

Protein: Enzymes

• Role in metabolism.
• Enzymes are protein catalysts that accelerate biochemical reactions in living organisms without being used up in the process.
• Involved in both anabolic (building new molecules) and catabolic (breaking down molecules) processes.
• Play a critical role in processes such as photosynthesis, cellular respiration, and digestion of food.

Enzymes

• The lock and key theory specifies that the enzyme has a specific active site that matches the shape of its substrate.
• When the substrate binds to the enzyme, an enzyme-substrate complex is formed..
• The substrate undergoes a process or chemical reaction, either breaking down or rearranging into new products.
• The products are released, and the enzyme remains unchanged and free to act on another substrate.

Industrial Uses of Enzymes

• Biological washing powders feature protease to break down protein stains like blood/egg.
• Leather production enzymes help in processing animal hides.
• Brewing industry enzymes aid in the beer-making process.

Proteins

• Examples include albumen, enzymes, and haemoglobin.
• Contain carbon, hydrogen, oxygen, and nitrogen; some may contain sulfur or phosphorus.

Properties

• High temperatures denature proteins, causing them to lose their shape and function.
• Low temperatures render enzymes inactive.
• Enzymes are highly specific.

Source

• Animal sources: fish, meat, eggs.
• Plant sources: nuts, beans.

Function

• Proteins growth and repair of body tissues.
• Speed up chemical reactions as enzymes
• Act as chemical messengers as hormones in the blood
• Haemoglobin is a protein in blood that carries oxygen and carbon dioxide.

Explore the fundamental concepts of chemistry and biology, related to fats, proteins, minerals, and water's unique properties and their functions. Understand the difference between saturated and unsaturated fats, protein composition, and water's role as a universal solvent.