Chapter 2.3: Chapter 2.3: Chemistry of CellsChemistry of Cells

BiochemistryBiochemistry

Organic CompoundsOrganic CompoundsOrganic molecules are molecules that Organic molecules are molecules that

contain Carbon atoms bonded usually to contain Carbon atoms bonded usually to Hydrogen, Oxygen or other Carbon atoms.Hydrogen, Oxygen or other Carbon atoms.

The four most important organic The four most important organic compounds found in living things are:compounds found in living things are:

- Carbohydrates- Carbohydrates

- Lipids- Lipids

- Proteins- Proteins

- Nucleic Acids- Nucleic Acids

CarbohydratesCarbohydrates (The dreaded carb!)(The dreaded carb!)

Made of Carbon, Hydrogen and Oxygen.Made of Carbon, Hydrogen and Oxygen.For every Carbon atom there is an Oxygen For every Carbon atom there is an Oxygen

and two Hydrogens. 1 : 2 : 1and two Hydrogens. 1 : 2 : 1 Carbohydrates are a huge source of energy.Carbohydrates are a huge source of energy. Carbs are made of single sugar molecules Carbs are made of single sugar molecules

called monosaccharides.called monosaccharides. An example of a monosaccharide is glucose An example of a monosaccharide is glucose

CC66HH1212OO66 Notice the ratio! Notice the ratio!

Carbohydrates cont.Carbohydrates cont.

Does this look familiar?Does this look familiar? This is a monosaccharide This is a monosaccharide

called glucose.called glucose. A single sugar molecule A single sugar molecule

can easily be pieced can easily be pieced together with another sugar together with another sugar to make a disaccharide.to make a disaccharide.

When this is done 1 When this is done 1 molecule of water is molecule of water is released.released.

Forming a disaccharideForming a disaccharide

Notice that when you remove a water molecule the two Notice that when you remove a water molecule the two molecules bond together to form a much larger molecules bond together to form a much larger molecule.molecule.

What do you think will happen if you throw in a water What do you think will happen if you throw in a water molecule?molecule?

Forming a carbohydrateForming a carbohydrate

If you take more than If you take more than two glucose two glucose molecules and bond molecules and bond them together you them together you form a form a polysaccharide.polysaccharide.

Each one of the little Each one of the little blue hexagons = a blue hexagons = a glucose moleculeglucose molecule

Examples of CarbohydratesExamples of Carbohydrates What is the carbohydrate that is What is the carbohydrate that is

stored in plants?stored in plants? Hint:Hint: StarchStarch

The carbohydrate that is found in The carbohydrate that is found in animals is called animals is called glycogen.glycogen.

These polysacharides store a lot These polysacharides store a lot of energy in the form of sugar.of energy in the form of sugar.

Sugar turns into fat.Sugar turns into fat. Hence the carb dietHence the carb diet When you break down a When you break down a

polysaccharide not only do you polysaccharide not only do you lose water you release energy.lose water you release energy.

LipidsLipidsA A LipidLipid is a non-polar organic molecule is a non-polar organic molecule

that is one of the principal structural that is one of the principal structural materials of living cells.materials of living cells.

A lipid is not soluble in water… Why?A lipid is not soluble in water… Why?Lipids are oily or greasy in texture.Lipids are oily or greasy in texture.Examples of lipids are fats, phospholipids, Examples of lipids are fats, phospholipids,

steroids and wax.steroids and wax.Some lipids can be pieced together to Some lipids can be pieced together to

form larger molecules.form larger molecules.

PhospholipidsPhospholipids

Phospholipids, like Phospholipids, like fat, and cholesterol fat, and cholesterol are made of two are made of two distinct parts.distinct parts.

- Glycerol - Glycerol

(Polar Head)(Polar Head)

- Fatty Acid tails - Fatty Acid tails (Non-polar tail)(Non-polar tail)

Phospholipids Cont.Phospholipids Cont.

If you take a bunch of phospholipids and put If you take a bunch of phospholipids and put them in water what do you think might happen?them in water what do you think might happen?

Because of the properties of phospholipids, Because of the properties of phospholipids, when in the presence of water a group of them when in the presence of water a group of them will form what is called a phospholipid bi-layer. will form what is called a phospholipid bi-layer.

This is what makes up the cell membrane.This is what makes up the cell membrane.

FATFAT

FatFat – a lipid in an – a lipid in an organism that stores organism that stores ENERGYENERGY..

Fat is also made of Fat is also made of glycerol and fatty acids.glycerol and fatty acids.

Glycerol is an alcohol Glycerol is an alcohol Fatty acids are a bunch Fatty acids are a bunch

of Carbons bonded to of Carbons bonded to HydrogensHydrogens

Do you notice any similarity between a fat and a

phospholipid?

Different types of fatDifferent types of fat There are two different types of fat that There are two different types of fat that

store energy in the body.store energy in the body.

1.1. Saturated fatSaturated fat – The Carbons in the fatty – The Carbons in the fatty acid are all bonded to two Hydrogens, acid are all bonded to two Hydrogens, except for the last which is bonded to except for the last which is bonded to three. This forms a straight molecule.three. This forms a straight molecule.

2.2. Unsaturated fatUnsaturated fat – Some Carbons are – Some Carbons are only bonded to one Hydrogen, making a only bonded to one Hydrogen, making a double bond and causing a kink in the double bond and causing a kink in the chain.chain.

Saturated and Unsaturated FatSaturated and Unsaturated Fat

Which fat is the “bad” fat? Why?Which fat is the “bad” fat? Why?

ProteinProteinProteinsProteins are made of a chain of amino are made of a chain of amino

acids linked together.acids linked together.Great! What’s an amino acid?Great! What’s an amino acid?Amino AcidAmino Acid – The building blocks of a – The building blocks of a

protein. There are 20 different amino protein. There are 20 different amino acids, each with a different chemical acids, each with a different chemical structure.structure.

All amino acids are made of Carbon, All amino acids are made of Carbon, Hydrogen, Oxygen and Nitrogen.Hydrogen, Oxygen and Nitrogen.

Some of the 20 amino acids are made of Some of the 20 amino acids are made of sulfur.sulfur.

Proteins cont.Proteins cont. Each amino acid has a similar chemical Each amino acid has a similar chemical

structure but different functional groups.structure but different functional groups.

Another type of functional group is the “R” Another type of functional group is the “R” group. This is what gives us our 20 different group. This is what gives us our 20 different amino acidsamino acids

Proteins cont.Proteins cont.

Some amino acids are polarSome amino acids are polar Some amino acids are electrically charged.Some amino acids are electrically charged. These give proteins a very distinct shape.These give proteins a very distinct shape.

Nucleic Acids… an introNucleic Acids… an intro

Nucleic AcidNucleic Acid – a long chain of nucleotides. – a long chain of nucleotides.Once again… Great! What’s a nucleotide?Once again… Great! What’s a nucleotide?NucleotideNucleotide – part of a nucleic acid that has – part of a nucleic acid that has

three parts.three parts.

1. Sugar1. Sugar

2. Nitrogen base2. Nitrogen base

3. Phosphate group3. Phosphate group

NucleotidesNucleotides

Nucleotides are put together to make a Nucleic Acid like so…

Nucleic AcidNucleic Acid

Nucleic Acids cont.Nucleic Acids cont.

There are two types There are two types of nucleic Acidsof nucleic Acids

- Deoxyribonucleic Acid - Deoxyribonucleic Acid (DNA)(DNA)

Double strandedDouble stranded

- Ribonucleic Acid - Ribonucleic Acid (RNA)(RNA)

Single strandedSingle stranded

ATPATPATPATP – Adenosine tri-phosphate – Adenosine tri-phosphate

(ENERGY)(ENERGY)A single nucleotide with two extra A single nucleotide with two extra

phosphates.phosphates.Main energy resource for cells.Main energy resource for cells.Energy from carbs and fat are stored Energy from carbs and fat are stored

temporarily as ATP.temporarily as ATP.When ATP is broken down it turns into When ATP is broken down it turns into

ADP and releases energy.ADP and releases energy.

ATPATP

When one of the phosphate groups are broken off Energy is released

ATP cycleATP cycle