Biology Unit 1: Cellular Functions Did you know that most organisms are made of only 6 common elements? Within cells these few molecules combine in many different ways to carry out a variety of functions that are the key to life.

The invention of the electron microscope allowed scientist to study the internal structures of the cell which lead to the cell theory: 1. All living things are composed of cells 2. Cells are the smallest functional unit of life 3. All cells come from preexisting cells. The cell can also be explored through chemical knowledge and procedures.

Biochemistry is the study of the chemistry of living things, including the chemical substances and processes involved.

Molecular Basis of Life 3. Macromolecules : Carbohydrates Proteins Lipids Nucleic Acids The molecules of life that nourish, build and direct cell activity include: 1. Water 2. Organic Compounds

Living Organisms Need: H 2 0, O 2 and CO 2 Cellular Respiration is the process by which cells release energy from oxygen and simple food molecules What is the equation for cellular respiration?

C 6 H 12 O 6 + 6O 2  6CO 2 + H 2 O + Energy Cellular Respiration

Water: The Primary Molecule of Life The most abundant molecule in any cell. Transport materials in/out of the cell. Raw material for essential cell reactions. Lubricant between organs, tissues and individual cells. Remains liquid over a wide temperature range and changes temperature gradually allowing for a stable environment. Expands when it becomes a solid.

Water These properties of water are determined by its chemical structure. Water molecules have an uneven distribution of charge and are polar. This allows water molecules to attract each other.

Organic Compounds Refer to molecules that contain both carbon and hydrogen. May also contain O, N, P, S Hydrocarbons refer to molecules containing only carbon and hydrogen. Covalent bonds (share electrons) Include macromolecules such as carbohydrates, lipids, proteins and nucleic acid.

Carbohydrates: carbon + water Provides short or long term energy storage Monosaccharides (simple sugar) –Made of carbon chains that are 3-7 carbons long. –Glucose is the most common and is a 6 carbon sugar (hexoses) with the formula C 6 H 12 O 6 –Trioses (3 carbon sugars) & pentoses (5 carbon sugars) are also common. –Main fuel for cellular work –When not used immediately, they are generally stored as disaccharides and polysaccharides.

Monosaccarides

Disaccharides 2 monosaccharides joined through dehydration synthesis ( water is removed) Glucose + Glucose = Maltose (brewing of beer) Glucose + Galactose = Lactose (milk) Glucose + Fructose = Sucrose (table sugar)

Polysaccharides A few hundred to a few thousand monsaccharides joined together. Storage polysaccharides – Starch, Glycogen Structural polysaccharides – Cellulose

Starch (Storage) Starch is the energy storage in plants. Glycogen performs the same function in animals. Glycogen molecules hold more glucose units than starch due to their branching structure. Examples include: Grains, Potatoes, Rice

Cellulose (Structure) Cellulose is produced by plants and used as part of the cell wall. It protects cells and provides support for the plant It also contains a large amount of energy that is not available to humans. Only a few bacterial species contain the necessary enzymes to break down cellulose, these bacteria live in the guts of cattle, rabbits and termites. However they are not found in humans. That’s why we cannot break down food such as Celery!