BIOMOLECULES

Carbon Compounds in Cells

Organic Compounds

• Organic compounds consists of carbon and one or more additional elements covalently bonded to one another

Biomolecules

• Those molecules that make up living things

Importance of Carbon• Carbon has the ability to covalently bond to

at as many of four other atoms.

• Carbon has the ability to rotate freely around a single covalent bond

• As a result carbon has the ability to form many varied structures

Hydrocarbons

• Organic compounds that contain carbon and hydrogen

Functional Groups

• Atoms or groups of atoms that are attached to carbon backbones, that convey distinct properties, such as solubility and chemical reactivity.

3 Types of functional groups

1. Hydroxyl group - OH

2. Carboxyl group - COOH

3. Amines - NH2

How Cells Use Organic Compounds

1. Biosynthesis Reactions - two molecules are joined together to form a larger molecule.

2. Hydrolysis - a molecule is broken down into two smaller molecules as a result of the addition of water

3. Enzymes - a special class of proteins that speed and initiate all chemical reactions in cells

Important Biological Compounds

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic Acids

5. Vitamins

6. Minerals

Carbohydrates

• Composed of carbon, hydrogen, and oxygen

• Functional groups present include Hydroxyl groups

• See pg. 53

Function of Carbohydrates in Cells

1.The breakdown of carbohydrates in our cells are the major source of energy for the cell. This energy can then be used by the cell for a variety of different processes

2.Major structural component of plant cells

Classification of Carbohydrates

• Carbohydrates are classified according to the number of sugar molecules that make them up

3 Types of Carbohydrates1. Monosaccharides

2. Disaccharides

3. Polysaccharides

Monosaccharides

• Carbohydrates`that consist of only a single sugar unit

• include glucose, fructose, galactose (pg 53)• These monosaccharides serve as the building

blocks for much larger carbohydrates.• Glucose is the major source of cellular energy in

cells

Disaccharides

• Composed of 2 monosaccharides

• cells can make disaccharides by joining two monosaccharides by biosynthesis.

• Ex. Glucose + fructose = sucrose

Glucose + galactose = lactose

See page 54

Polysaccharides• Composed of 3 or more

monosaccharides

• made by way of biosynthesis of cells

Types of Polysaccharides

1. Starch - composed of hundred of thousands of glucose molecules

- made by plants to store energy for future use

- easily hydrolized into individual glucose

Types of Polysaccharides

2.Cellulose - form cell walls in plant cells

- also called fiber or ruffage

- indigestible by humans

Types of Polysaccharides

3.Glycogen - made in animal cells

- made for the purpose of short term energy storage

- stored in liver and muscles

Types of Polysaccharides

4.Chitin - a specialized polysaccharide that has nitrogen attached to it

- forms exoskeleton of arthropods

Lipids

• Lipids are nonpolar and do not dissolve in water

• composed of carbon, hydrogen, and oxygen

• contain the carboxyl functional group

Function of Lipids1.Storage of energy in animals

• animal cells will convert excess carbohydrates into lipids to be stored for later use

2. Key component in cell membranes

Function of Lipids

3.Cushion for delicate organs

4.Carriers for vitamins A, D, E, K

5. Serve as the raw materials for the production of hormones

6.Insulation against the cold

Key Components of Lipids

• Fatty acids are key components of many lipids

• unsaturated fatty acids are liquid at room temperature composed of double bonds

• saturated fatty acids are solid at room temperature and contain only single bonds

Types of Lipids1.Triglycerides

• formed by the union of 3 fatty acids and an alcohol called glycerol

• those composed of saturated fatty acids are called fats and are made in plants

• those that are composed of unsaturated fatty acids are called oils and are found in oils

• excess carbohydrates in the body are converted to triglycerides until the energy is needed.

Types of Lipids2.Phospholipids

• composed of glycerol and fatty acids as well as phosphate groups

• are a major component of cell membranes

Types of Lipids

3.Waxes

• composed of very long chains of fatty acids

• serve as waterproof coating for plant leaves, animal fur, and feathers

Types of Lipids

4.Sterols

• serve as building blocks for hormones

Proteins

• Composed of carbon, hydrogen, oxygen, and nitrogen

• contain the carboxyl group and the amine group

Function of Proteins

• Serve as the raw materials for the building of new cells and tissues

• Help in disease fighting

• Serve as transport agents in the body

• Help to speed and initiate chemical reactions (enzymes)

Key Components of Proteins

• Proteins are composed of smaller units called amino acids

• there are 20 different types of amino acids

• the average protein is about 200 A.A. long

• A.A acids can combine in millions of different ways to form millions of proteins

Protein Shape and Function

• Every protein made by the cell has its own distinctive shape

• it is the shape of the protein that helps to determine its function

Enzymes - Special Proteins

• All reactions that take place in our cells are initiated and sped up as a result of a SPECIFIC enzyme.

• All reactions require enzymes or they will not occur or occur much to slowly

• Enzymes are catalysts (see glossary)

Enzyme’s effects on Activation Energy

Enzymes and Environment

• High temperatures or changes in pH can cause an enzyme to lose its normal 3-D shape ( denaturation )

• this denaturation causes the enzyme to lose its normal functioning

Nucleic Acids

• Composed of building blocks called nucleotides

• 2 main types– deoxyribonucleic acid (D.N.A)– ribonucleic acid ( R.N.A)

Minerals

• See pg. 642

Vitamins

• See page 642