AP

Chemicals of Life(in depth)

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

  1. 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.%%

  1. 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.

  1. 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.

  1. 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.

  1. 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.

  1. 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.%%

  1. 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%%
  1. 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

  1. Inorganic Phosphate (H3PO4)

  2. 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)