Chemistry of Cells

Has nothing to do with being naturally occurring!!

Carbon skeletons vary in length.

Branching. Skeletons may be unbranched or branched.

Butane Isobutane

PropaneEthane

Double bonds.

2-Butene

Skeletons may have double bonds,which can vary in location.

Cyclohexane

Length.

1-Butene

Benzene

Skeletons may be arranged in rings.Rings.

These are hydrocarbons

Study molecules important to life

4 Main Groups

What elements do they contain??????

1) Monosaccharides (Simple sugars)Examples:

-glucose

-fructoseBLOOD SUGAR

FOUND IN FRUITS

Function energy (readily available)

-Ribosefound in RNA

Structure:

Glucose

Elements?Shape?

Dehydration reaction-build larger molecules (polymers) by adding additional

subunits (monomers)

Hydrolysis reaction-breaks the polymer down by adding water

Disaccharides• Examples:

– Sucrose– Lactose– Maltose

•Functions

- Energy

Structure:formed from the joining of two monosaccharides

Maltose

General Structure:Many monosaccharides linked

togetherExamples: Cellulose

Monomer = glucoseFunction:

structural component of cell walls

Polysaccharides

Polysaccharides

• Starch– Made of glucose monomers– Found in plants– Energy storage for plants

Glycogen

• Glucose monomers

• How animals store glucose– In liver and muscles

Fig. 3-7

Starch granules inpotato tuber cells

Glycogengranulesin muscletissue

Cellulose fibrils ina plant cell wall

Cellulosemolecules

Glucosemonomer

GLYCOGEN

CELLULOSE

Hydrogen bonds

STARCH

Chitin

• Found in the exoskeletons of arthropods

• Function????

Proteinsstructure

• Are polymers

• Made from chains of amino acids

• Linked by peptide bonds– Those bonds form through dehydration

reaction

Fig. 3-12a

Carboxylgroup

AmiNogroup

Structure of an amino acid

Fig. 3-12c-1

Carboxylgroup

Amino acid

Aminogroup

Amino acid

Fig. 3-12c-2

Carboxylgroup

Amino acid

Aminogroup

Amino acid

Peptidebond

Dipeptide

Dehydrationreaction

Build the polypeptide (protein) by dehydration reactions connecting the carboxyl group of one amino acid to the amino group of the other amino acid.

Fig. 3-12b

Leucine (Leu)

Hydrophobic

Serine (Ser)

Hydrophilic

Aspartic acid (Asp)

Different amino acids have different properties. Help to determine the overall shape of the protein

Functions

Structural proteins collagen, keratin, cell skeleton

Storage ovalbumin

Transport cell membrane transport protein, hemoglobin

Regulation hormones (insulin)

communication receptor proteins on nerve cell membranes

Movement in muscles

Defense antibodies

enzymes molecules that accelerate chemical reactions

Hemoglobin

collagen

Insulin

actin

myosin

Nucleic Acids• Are polymers

made of linked nucleotides

• Examples are DNA and RNA

Fig. 3-8a

Lipids

• Diverse group of hydrophobic molecules

Include fats, phospholipids, and steroids

General structure of a fat

3 fatty acid chains

Fig. 3-8b

Fatty acid

GlycerolBuilt by dehydration reactions

Fatty acids (and the fats that contain them) can be saturated or unsaturated

Saturated with hydrogens

Amount of Hydrogens

Shape of tails

Presence of double bonds

Solid or liquid (room temp)

Source/examples

Saturated

Unsaturated

Functions of fats• Energy

• Cushion

• insulation

Phospholipids

Structure:• Similar to fats, but a

fatty acid is replaced by a phosphate group

Function •Are a major component of plasma membranes

testosterone estrogen

cholesterolprogesterone

4 fused rings

Study molecules important to life

4 Main Groups