How are organic compounds different from inorganic compounds?

Why is water so important to living things?

Inorganic Compounds – derived from nonliving things

Organic Compounds – derived from living things and contain “C” - “H” & “O”

So, what would water (H2O) be??

1. A source of hydrogen & some oxygen

2. A medium for dispersal & transport

3. Most common solvent

Water’s biological functions stem from its chemical structure

In a water molecule the 2 hydrogen atoms are covalently bonded to the oxygen atom

Although electrons are shared, they are not shared equally

The oxygen atom has 8 protons in its nucleus to attract electrons

The hydrogen atom only has one proton

The nucleus of the oxygen atom more strongly pulls the shared electrons

As a result the electrical charge is unevenly distributed

The 3 atoms in a water molecule are not arranges in a straight line

The 2 hydrogen atoms bond with the oxygen atom at an angle

The total electrical charge on the molecule is zero

But the area where oxygen is located is slightly negative and the areas where the 2 hydrogens are located are slightly negative

Makes water effective at dissolving many other substances› Sugars› Some proteins› Ionic compounds**NaCl – ionic compound that dissociates

into Na+ ions and Cl- ions in water. **Important for essential body functions

such as muscle contraction and the sending of nerve impulses

Polar water molecules are attracted to eachother

A hydrogen bond forms between a slightly positive H atom in one water molecule and a slightly negative oxygen atom in another water molecule

So, water clings to itself and to other substances

Cohesion – attractive force between particles of the same kind

Water molecules are cohesive The hydrogen bonds cause water to

act as if it has a skin on its surface This is called surface tension Water appears to bulge from the

sides of objects

Adhesion is the attractive force between unlike substances

Capillary Action - Adhesion + Cohesion allows water molecules to move up through narrow tubes against the force of gravity

You can observe the flow of colored water up through a stem and into a flower

Contain carbon atoms that are covalently bonded to other carbon atoms

Carbon atoms are usually bonded to other atoms as well – H, O and N

The chemistry of carbon is the chemistry of life

Has four electrons in outer shell:

It wants to fill its outer shell with 8 electrons

It can form four covalent bonds with itself or other elements

It can combine in many ways(chains, branches, and rings)

It can form double or triple bonds Functional groups – clusters of atoms

attached to the carbon determine the characteristics of a compound (OH)

Large molecules are built up from smaller molecules – monomers

Monomers bond together to form polymers (larger molecules of repeated, linked units)

Large polymers are called macromolecules

Monomers link together to form polymers in a chemical reaction called a condensation reaction or a dehydration synthesis reaction

As the monomers link together, a molecule of water is released

The breakdown of a complex molecule or polymer occurs through a hydrolysis reaction

This is the reverse of a condensation reaction

Water must be added to separate the monomers

Life processes require a constant supply of energy

Adenosine triphosphate (ATP) has 3 phosphate groups attached to each other by covalent bonds

When bond that holds the last phosphate group is broken – lots of energy is given off

This energy drives the chemical reactions within each cell

Complete carbon compounds activity

Finish for homework if not completed in class

Why is carbon so commonly bonded to itself and other atoms?

What type of reaction results in the formation of polymers?

What type of reaction breaks down polymers?

THERE ARE “FOUR” DIFFERENT CLASSES OF ORGANIC COMPOUNDS› Carbohydrates› Lipids› Proteins› Nucleic Acids

Organic compounds of C, H and O

Used as energy sources in cells

Also found in several cellular structures such as bacterial capsules

They are synthesized from water and carbon dioxide during photosynthesis

Monosaccharides are the simplest carbohydrates

They are the building blocks for the larger carbohydrates (polysaccharides)

Glucose, galactose and fructose are examples of isomers – they have the same chemical formula C6H12O6

But their structures and properties are different

Represents the basic supply of energy in the world

Half of the world’s carbon exists as glucose

Double sugars – composed of two monosaccharides held together by covalent bonds

They are made from glucose molecules through dehydration synthesis – water is removed as the new bonds are formed

Examples are:› maltose – found in barley and used to ferment beer› lactose – found in milk and digested by bacteria to

form yogurt, sour cream› Sucrose – table sugar and is the starting point in

wine fermentation and may be a cause of tooth decay

Complex sugars

Large compounds formed by joining together 100’s or 1000’s of glucose molecules› Starch – used by bacteria as an energy

source› Cellulose – a component of the cell walls of

plants and molds and also used as an energy source by microorganisms

What are the 4 classes of organic compounds?

What 3 elements are carbohydrates made up of?

What carbohydrate is considered a universal source of energy?

Dissolve in organic solvents, but not in water

Like carbohydrates, they are composed of C, H, and O, but with much less O

The best known lipids are fats

Fats are important long-term energy sources for living things

Fats are also components of cell membranes

Fats consist of a 3 carbon glycerol molecule and up to 3 long-chain fatty acids

2 major types of fatty acids:› Saturated – contain the maximum number

of H atoms› Unsaturated – contain less than the

maximum number of H atoms› Unsaturated fatty acids are good for us –

they lower the levels of cholesterol in the blood

Overhead Master #7

What are the facts about saturated fat? 

 

  

If the carbon atoms (C's) in a fat have all the hydrogen atoms (H's) that they can hold, the fat is saturated.

Lipid molecules are sparingly to insoluble in water. Lipids are hydrophobic because the molecules consist of long, 18-22 carbon, hydrocarbon backbones with only a small amount of oxygen containing groups. Lipids serve many functions in organisms. They are the major components of waxes, pigments, steroid hormones, and cell membranes. Fats, steriods, and phospholipids are very important to the functioning of membranes in cells and will be the focus of this tutorial. Fats (triacylglycerols)

Other types of lipids:› Waxes – long chains of fatty acids

Bee’s wax Plant leaves

› Phospholipids – contain a phosphate group Cell membranes

› Steroids – composed of several rings of carbon atoms with side chains Cholesterol Estrogen Testosterone

What are fats used for in your body? What is the difference between

saturated and unsaturated fats?

Most abundant organic compounds of living things They can be:

› Structural› Enzymes – regulate the rate of chemical reactions

They are composed of chains of amino acids

Each amino acid contains› Carbon atom› Amino group (NH2)› Carboxyl group (COOH)› Functional (R) group - what makes the 20 AA’s different

Amino acids are joined together by peptide bonds› 2 AA’s – dipeptide› More than 2 AA’s - polypeptide

The sequence of amino acids is extremely important because one mistake changes the protein (mutations)

Protein Structure:› Primary – AA sequence› Secondary – AA chain twists into a corkscrew

or sheet pattern› Tertiary – Protein folds back upon itself› Quaternary – Multi-unit cluster

Enzyme - protein that acts as a catalyst

They lower the amount of activation energy needed for a reaction to occur

Depends on a physical fit between the enzyme molecule and its substrate (lock and key)

As they link, the enzyme changes shape and some of the substrate's chemical bonds are weakened

Insulin – protein that regulates the metabolism of carbohydrates and fats

People with diabetes don’t produce enough insulin

If we could understand insulin’s structure, we could make it in the lab as a drug

Frederick Sanger – broke insulin code; used chromatography to identify the kinds and amounts of amino acids

Some of the largest molecules found in organisms› DNA – genetic material in the chromosomes

that carries the genetic code› RNA – cell messenger that functions in protein

construction

Composed of nucleotides – 3 parts› Carbohydrate molecule (ribose or deoxyribose)› Phosphate group› Nitrogenous base

DNA – adenine, guanine, cytosine, thymine RNA – adenine, guanine, cytosine, uracil

DNA is located in the chromosomes of the cell

It passes on the genetic information and directs protein synthesis

DNA molecule consists of 2 single strands of DNA in opposite directions arranged in a double helix ladder:› Sides of ladder – sugar and phosphate› Rungs of ladder – paired nitrogenous bases

DNA in the nucleus carries the genetic code

DNA gets transcribed into messenger RNA (mRNA) in the nucleus

mRNA leaves the nucleus and brings the code out into the cytoplasm of the cell

mRNA gets translated into protein with the help of transfer RNA (tRNA) and ribosomes