Carbohydrates

Elements present- C, H and O. Preset in a C1H2O1 ratio.

Function- Energy and structure.

3 different types

1. Monosaccharides (simple sugars). The building blocks.

Eg. Glucose, Ribosome, Fructose, Galactose.

Monosaccharides are distinguished by the carbonyl group(aldehyde or ketone) and the number of atoms in the carbon backbone.

Carbohydrate configurations can be drawn in 2 ways. Chain form and ring form. The chain form shows functional units better but the ring form is more accurate to shape. The ring is the only shape normally found in biology.

Eg. A glucose molecule.

A 6 sided ring is called a pyranose ring. And the OH group on C#1 can be found above or below the midline of the ring. If it is below it is an alpha glucose and if it is above it is called a beta glucose. 50% become alpha and 50% become beta.

Chain form of glucose.

Ring form of glucose.

Fructose, galactose ad mannose are all examples of isomers to glucose.

Note: an isomer is a molecule that shares the same chemical elements but different structure.

Eg. Ribose and Fructose.

Ribose.

Fructose

2. Disaccharides

Disaccharides are more complex sugars. Simple sugars joined together with condensation and ether links

Eg. Maltose= glucose+glucose

Linkages are either 1,4 glycosidic or 1,6.

The carbon 1 of on molecule is connected to the carbon 4 of the other.

3. Polysaccharides

A polysaccharide is when many simple sugars join together using 1,4 or 1,6 ether links.

Note: Oligosaccharides: smaller polysaccharides (3-10 monosaccharides)

Eg1. Starch

Starch is a storage molecules in plants. It stores glucose. It is made up of 2 smaller polysaccharides.

It is 25% amylose- a glucose linked using 1,4 linkages to get a coiled chain. And 75% amylopectin- glucose linked using 1,4 and 1,6 linkages that form tangled short branches.

The more branches the starches are, the harder they are to digest.

Eg2. Cellulose.

Main component of plant cell walls. Made by joining 3000+ glucoses w Beta 1,4 links.

We have no enzymes that can digest this linkage. And the straight unbranched shape allows hydroxyl groups of parallel molecules to form hydrogen bonds and produce tight bundles or fibres.

Eg3. Glycogen (animal starch)

This form of glucose is store in live/muscle. It is shaped like amylopectin but even more 1,6 links so more branched.

Eg4. Chitin

A special polysaccharide found on the coverings of insects and crustaceans. It is not a true polysaccharide due to the nitrogen.

Eg5. Blood groups (A,B,AB,O)

Different blood types cause by the 2 different polysaccharides attached to the membrane of a RBC(red blood cell).

Lipids

Elements present- C,H,O and P(sometimes).

Functions- energy, structure(cell membranes), regulatory jobs(hormones,steroids,insulation, shock absorber)

Types of Lipids

1. Fats

Most common energy storage. They are energy storage efficient because they are compact and lightweight. Made of a long chain of fatty acids joined to a glycerol with an ester bonds.

Glycerol is the hydroxyl and fatty acids are carboxyl. Usually contain even amounts of carbons(14,16,18) and may be saturated or unsaturated. A saturated fat has only single bonds. A unsaturated fat has double/triple bonds that cause kinks.

Different lipids are caused by…

I) types of fatty acids joined to glycerol

II)amount of fatty acids

• 1 F.A = monoglyceride

• 2 F.A= diglyceride

• 3 F.A triglyceride

Results in…

I) Fats contain long fatty acids and are saturated.

II) Oils contain short fatty acids and are unsaturated.

2. Phospholipids

Lipids by themselves are non-polar and do not like water. BUT phospholipids have one polar end that attracts water and another end that is still non-polar. They are made up of glycerol, fatty acids and 1 phosphate containing a functional group.

3. Steroids

Compact hydrophobic molecules, 4 fused hydrocarbon rings and several different functional groups.

Eg1. Sex hormones- estradiol in female, testosterone in male, they only have a couple small differences.

Eg2. Cholesterol- important in membranes and structure. Cells convert it into vitamin D and bile salts.

4. Waxes

Waxes are long chains of fatty acids linked to alcohol or carbon rings. Ester links.

Eg. Honey comb, earwax, beeswax

Triglyceride (Macromolecules)

Main molecules for energy storage. 1 glycerol + 3F.A. It is an overall non-polar molecules. The oxygens do create a small polar section but it does not affect the non-polarness of the molecule.

The first 2 fatty acid chains are saturated due to all the carbons being bonded by single bonds. But the bottom chain has a double bond and a kink which makes it unsaturated.

Proteins

Functions:

1. Structure (muscles, hair, skin, nails, bone)

2. Energy

3. Regulatory (controls enzymes)

Structure:

Protein macromolecules- amino acids linked together via peptide links.

Types of Proteins

Depends on:

1. amount of amino acids (AA) linked together

2. Type of AA linked together (Different side chain combos)

3. Sequence of AA

Protein function is dependant on shape!!!

Protein Structures:

1. Primary

2. Secondary

3. Tertiary

4. Quaternary

All proteins have the first 3.

1. Primary

Number, type and sequence of amino acids linked together in a chain.

All other structures depend on primary.

2. Secondary

Formed when hydrogen bonds are created between amino acids along the chain.

2 structures can be formed:

• Alpha-Helix

When the electronegative oxygen of 1 peptide link is attracted to an électropositive H of another peptide link.

• Beta-sheet

When 2 peptide chains that lie parallel to each other have H-bonds form between them due to the oxygen of one peptide link attracting to the H of the adjacent peptide link.

3. Tertiary

Makes the overall structure of protein. Folding created due to R-group interactions. Polar R-groups will fold to the outside (hydrophilic) while non-polar R-groups will fold inwards (hydrophobic).

3D shape is stabilized by R-group interactions

• H-bonds between R-groups

• Ionic bonds between charged R-groups

• Disulphide Bridge between R-groups that contain sulfur

• Dipole-dipole forces

4. Quaternary

Not all proteins contain this!

Multiple subunits formed together to create a functional protein.

Subunit→ polypeptide chain folded into tertiary structure

Eg. Hemoglobin has 4 units (2 alpha, 2 beta)

Nucleic Acids

Functions: cell coordinations- instructions for cell functions

Structure: Nucleotides

1. pentose sugar (5 carbon sugar)

Eg. Deoxyribose or Ribose

2. Inorganic Phosphate (H3PO4)

3. Nitrogenous Base- nitrogen containing a ring (2 types)

• Pyrimidine(single ring)

Eg. Thymine, Cytosine

• Purines (double ring)

Eg. Adenine, Guanine

Multiple Nucleotides combine to create DNA and RNA (cell information)

Energy Relationship- ATP

Nucleotides provide immediate energy sources for most activities in living cells.

• act as mobile potential energy storage molecules

• Can act as coenzymes- accept and donate e- or h+ in redox reactions

1. Adenosine Triphosphate (ATP)

• made of ribose sugar + adenine + 3 phosphate groups (It’s a nucleotide)

• It is formed when ADP + Pi → ATP

• Very acidic due to 4 H protons on phosphate disassociates. Leaves area with -ve charge.

O- is unstable, energetic and holds potential energy.

P Anhydride Linkage

• repulsion of all the -ve charges lead to highly energetic area.

• Represented with a squiggly line.

• Means that a large amount of useful energy is released when the bond is broken by hydrolysis

• The product that results (ADP+Pi) have less free energy than reactants. (ATP+H2O)

Enzymes

• are proteins

• Catalyze chemical reaction

• Like lock and key (fits specific shape)