Chemistry of Life

Bio A

Organic Molecules: molecules that contain both C and H; can contain other elements too;

- If they ONLY contain C and H they are called hydrocarbons

Why can carbon make these long chains?

CWants to share all its electrons

Therefore C can make up to 4 covalent bonds at a time!!

Draw each structure beside the appropriate description. One of the descriptions does NOT have a structure shown

Organic Molecules: When you cannot follow a line of carbons in a molecule without “backtracking” the molecule is branched.

2-methyl butane

Using skeletal structures• Skeletal structures are used only for organic

molecules. • Since all organic molecules contain C and H,

we only fill in things on the structure that ARE NOT C or an H that is directly attach to a C or H

• We draw a zigzag line to represent the line of carbons. Each vertex or endpoint signifies a carbon. LET’s try a few.

Draw skeletal structures of these molecules

Inorganic molecules: molecules that do not contain BOTH C and H

Some examples:

Compounds of the Cell:

MineralsWater Carbohydrates

Lipids Nucleic Acids

Proteins

WATER: most essential inorganic molecule

Body is 65- 75% on average

More in fat or muscle??

More in Males or females??

Functions of water:

Solvent: dissolves lots of stuff

Medium: where the chemical reactions happen

Moistens Surfaces:

What if your lungs were dry?

Functions of water: Temperature Regulation

Example? Cushion

Brain in skull;

Transportation

Moving molecules through the blood

Functions of water:

Hydrolysis

Using water to break apart large molecules

Lubrication

Joints; prevent bones from scraping

Functions of water:

Sense Organs

Eyes

Nose

Mouth

Minerals

Phosphorous

Iodine

Important minerals:

Iron

Calcium

Sodium

Chlorine

Potassium

Minerals

Function: help maintain fluid and electrolyte balance;

- act as a pH buffer

- aid in structure of cells (body)

- Move nerve impulses

- Carry oxygen

- Regulate thyroid gland (and metabolism)

The organic molecules we will study are known as Macromolecules

Macro = big

- made up of many small molecules linked together to form one big molecule

- small molecule = a monomer

- chain of small molecules = polymer

Nutritional Compounds

These Macromolecules are what provide us with nutrition

They make up the “Calories” we eat

Calorie ( in science): 1 unit of thermal (heat) energy

1 calorie (chemistry) is the amount of energy it takes to raise the temperature of 1 gram of water 1 degree Celsius

1 food calorie = 1000 chemistry calories = 1 kilocalorie

So, 1 calorie of food has enough energy to heat 1000g of water 1 degree.

Nutritional Label Handout

CARBOHYDRATES (CHO)

Monomer: Monosaccharides:

simple sugars;

5 carbon or 6

Carbon rings

Disaccharides: “double sugars”;

CARBOHYDRATES (CHO)

Polysaccharides: 3 or more single sugars; huge chain molecules

How do they connect?

- Dehydration synthesis: chemical reaction that joins monomers to make polymers; also creates a H2O

How do they connect?

- 2H’s and 1 O have to be removed to link reactants. These atoms form 1 water molecule

+

+ H2O

Dehydration Synthesis:

- Underline the atoms that become the H2O

How do we break them apart?

- Hydrolysis: chemical reaction that takes in a H2O to break polymers into monomers

+

H2O

Hydrolysis:

- Underline the atoms that WERE the H2O

CARBOHYDRATESWhat do they do?1.Monosaccharides – instant energy

2.Polysaccharides – short term energy storage (Starch vs. glycogen)

3.Structure of the cell – Plant cell wall

CARBOHYDRATES (CHO)Examples:

1.Starch (amylose)2. Sugar (Glucose, lactose, fructose…)

3. Fiber (cellulose)

What do they have in common?

Lipids

Made of: 1 glycerol + 3 Fatty Acids 1 Fat molecule

Lipids

Fat molecule is called a Triglyceride

LipidsNO TRUE MONOMER.

DOESN’T FORM A CHAIN

Lipids – NO MONOMER!Once we connect the three fatty acids to

the glycerol, we can not connect anything else.

No endless chains like with carbs, proteins and nucleic acids.

LipidsHow do the 4 parts combine?

Any guesses???

LipidsBut we need THREE reactions to make 1

triglyceride

Lipids

Include: fats, oils, waxes; steroids

LipidsFunction:

1. long term energy storage

2. Cell Structure: membrane

3. Cushioning

4. Insulation

Is Atkins or the South Beach diet really good for you??

Why has society become anti-carb?

Dieting:

Are fats and “carbs” really evil??

Proteins

Monomer: Amino acid

Amino end

-NH2

Carboxyl end

-COOH

Variable R group

NHH

CH

C OH

O

R

Amino acids form a chain called polypeptides.

- using same dehydration synthesis reaction

+

2 unlinked amino acids 1 polypeptide + H2O (not shown)

Polypeptides twist and fold into a 3D shape to make a protein

- only folded proteins are functional

ProteinsFunction: Example:

1.Structure - cartilage

2.Messengers - Hormones

3.Speed up chem. Reactions - Enzymes

4.Fight disease - Antibodies

Structure of Nucleic Acids

Nucleotides: monomer of nucleic acids

Three Parts of a nucleotide:

5 carbon Sugar – C, H, O

Phosphate group - PO3

Base – N, C, H

Structure of Nucleic Acids

P o

H

OH

H

H

H

BaseCH2

H

P = Phosphate = H2PO3

Structure of Nucleic Acids

So what elements are involved:

Sugar? PHOSPHate?NITROGENous base?

Nucleic Acids

General Role: “information molecules”; tell our body how to make/do what it needs to

Examples of Nucleic Acids

DNA:

Full name: deoxyribonucleic acid;

Sugar: deoxyribose

Possible bases: A, T, G, C

Number of chains: two twisted together

Function: “cookbook”, the master copy of information

Examples of Nucleic Acids

RNA:

Full name: ribonucleic acid;

Sugar: ribose

Possible bases: A, U, G, C

Number of chains: one spiral chain

Function: single recipe, temporary copy of the instructions for 1 protein

Nucleic Acids ANALOGY

DNA = cookbook, ALL the recipes

RNA = index card copy of 1 recipe

Protein = tasty food that is made from the recipe