Biology Prelim Topic 1 notes

Biology Study Term 1

Organic Compounds:

Water-
Provides an environment for metabolic reactions
The structure gives it a slightly positive and slightly negative charge giving it the ability to dissolve substances.
Carbohydrates:
The main function of carbohydrates is to provide an energy source
Carbohydrates can also be used for structural units such a deoxyribose.
Composed of Carbon, Oxygen and Hydrogen.
Monosaccharaides:
Composed of 3 to 7 carbons.
Prefixes indicate the number of carbons.
EG. Pentose=5 Carbons.
Main energy supplier to the body is a monosaccharaide called glucose!
Disaccharides:
Formed by two Monosaccharaides.
EG table salt. Formed by one alpha glucose and on Fructofuranose.
Polysaccharides:
Formed by 3 or more Monosaccharaides.
Mainly structural compounds.
EG cellulose.
Lipids:
Primarily fats. Oily and greasy consistency.
They repel water.
Long-term energy storage.
Store twice as much energy as carbohydrates.
Secondary function is as structural components.
Saturated Fatty Acids:
Most number of hydrogen atoms bonded to them. NO DOUBLE BONDS.
This results in straight structure.
Derived from animal’s fats such as butter.
Unsaturated Fatty Acids:
Typically derived from plant and fish fats.
Has at least one double bond.
One double bond=monounsaturated
Two or more are called polyunsaturated.
Proteins:
Play a very important structural role in growth and development.
Substance such as enzymes and antibodies are proteins.
Made of Carbon, Hydrogen, Oxygen and Nitrogen. Can also contain sulfur or phosphorus.
Made of very long chains of repeating units called amino acids.
20 different amino acids, which form to create new proteins.

Nucleic Acids:
DNA and RNA are Nucleic acids.
Made of two strands of nucleotides.
Made of 3 parts:
1. Phosphate
2. Nitrogenous Base
3. Pentose sugar
The four types of Nitrogenous bases are Adenine. Thymine, Guanine and Cytosine.
Vitamins:
Vitamins are essential for correct enzyme functioning
They are carbon-containing compounds and are only needed in minute amounts.
Minerals:
Inorganic compounds found in cells. Are necessary for correct metabolism.
Minerals are dissolved in water. By the body forms ions.
Essential minerals are:
Calcium- Bone development and blood clotting.
Iron- Red blood cells.
Chlorine- water and acid balance.
Potassium-Muscle contractions, nervous system.
Phosphorus- Energy transformation reactions.
Sodium- Water balance, nervous system.

Cells, Structure and Contents.
5 types: Monera, Protista, Plantae, Fungi and Animalia.
Prokaryotic:
No nucleus.
Few internal structures visible under a microscope.
Eukaryotic:
Have a membrane bound nucleus.
Many internal membrane bound structures EG. Chloroplast and mitochondrion.
Autotrophic Cells convert light into energy and create on “food”
Heterotrophic Cells need to obtain nutrition form environment.
Features of the Cell:
Cell Membrane-Flexible lipid layer, which is semipermeable, meaning it allows some molecules to pass through it.
Nucleus-The control center of the cell, only present in Eukaryotic Cells. Everything inside it is called Nucleoplasm. It contains DNA and therefore controls every function of the cells. It is surrounded by a double-layered membrane, which also is semipermeable. Inside of this is where RNA is produced which is vital to the production of proteins.
Mitochondria: Production of energy. Also bound with a double membrane layer, highly folded and large surface area for reactions to occur. Mitochondria has its own DNA and ribosomes.
Chloroplasts: Responsible for photosynthesis. These cells store light energy and convert in to glucose. Semipermeable-layered membrane.
Ribosomes: Are where proteins are synthesized and can be attached to endoplasmic reticulum. Help join amino acids into polypeptide chains which proteins are made of.
Vacuoles: Only in plants cells. Used for shape and structure of cells. Used to store nutrients, metabolics and waste products.
Cell Wall: Gives plant cells a very defined shape. Each cell wall interacts with its neighbor to form a tight bond.
Cell Theory:
The idea that all living things are consisted of cells.
All cells are produced due to the result of a division of existing cells.