Macromolecules

Guiding Questions

How does the structure of each biological molecule relate to its specific function?

How do enzymes impact chemical reactions in an organism?

Acids, Bases, and pH

Do you remember the pH scale?

Have you ever felt an acid vs a base?

pH scale is used to indicate the concentration of H+ ions in solution

H2O breaks down to H+ and OH-

Acids, Bases, pHSolutions with high concentrations of H+ are called acidic, 0-6 on the pH scale

Lemon juice, car battery, vinegar

Solutions with less concentrations of H+ are called bases, basic, or alkaline 8-14 on the pH scale

Bleach, ammonia, soap

BuffersBuffers are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH

An important way of controlling pH and maintaining homeostasis.

CarbonAnything that is made of carbon bonded molecules is called “Organic”

Carbon is special because it has 4 valence electrons and allows it to form strong covalent bonds with many other elements

All living things are made of molecules that consist of carbon bonded to other elements

Carbon can bond to itself easily and will therefore form long chains

More CarbonCarbon bonds an be single, double, or triple bonds

Carbon has the ability to form millions of different large and complex structures

No other element can even come close to matching this versatility

MacromoleculesJust what are macromolecules…

Do you think you can name any?

The 4 macromolecules are: Carbohydrates, lipids, Nucleic acids, proteins

Monomers vs Polymers

CarbohydratesThese are compounds made up of carbon, hydrogen and oxygen atoms

Ration of 1:2:1

Carbohydrates supply energy for cell activity

Some carbohydrates will be used for structure

Carbohydrates are actually all sugars

Simple Carbohydrates

Simple sugars are always known as monosaccharaides

Think monomers!

Found in many fruits, table sugar

Glucose (we will look at in a few units) is highly important to cell function.

Complex CarbsLarger macromolecules known as polysaccharides

Glycogen-animal starch

When glucose is too low(cell function), Glycogen is broken down instead

Glycogen helps muscle contraction

Cellulose in plants give it that rigid structure.

Also the major component in wood and paper

LipidsMade up of mostly carbon and hydrogen

Not soluble in water

Fats, oils, waxes

Can be used to store energy

Some are important biological membranes

Steroids are an important lipid

Can be saturated or unsaturated

Have a sugar end and a fatty acid tail

Lipids

SaturatedLipids where the fatty acid tail contains only single bonds

Called saturated because it contains the maximum number of hydrogen atoms

Unsaturated

Lipids where the fatty acid tail contains a double bond and therefore a “kink”

These fats are typically liquid at room temperature

Nucleic AcidsContain hydrogen, oxygen, carbon, and phosphorous

Assembled from individual monomers known as nucleotides

Store and transmit hereditary, or genetic, information.

Can be ribonucleic RNA

Can be deoxyribonucleic DNA

ProteinContain nitrogen, carbon, hydrogen, oxygen

Polymers made up of amino acids-you will see those in unit 6

Proteins are functional molecules built from one or more polypeptides

Some proteins control the rate of reactions and regulate cell processes

Others form important cellular structures

Others transport substances into or out of cells to help fight disease

Proteins and structure

There are 20 amino acids in natureAll these amino acids can bond to each other

Proteins are the most diverse macromolecule

Proteins form peptide bondsSpecial type of covalent bond

Chemical Reactions

A Chemical Reaction is a process that changes, or transforms, one set of chemicals into another.

Some chemical reactions occur fast, some slow

Elements or compounds that entre into a chemical reaction are know as reactants

Elements produced by a reaction are know as products

Chemical equations involve changes in the chemical bonds that join atoms in compounds.

EnergyEnergy is released or absorbed when chemical bonds are formed or broken

If energy is released, reactions occur on their own- Exothermic

If energy is absorbed, the reaction will need a source of energy to start.- Endothermic

Activation EnergyChemical reactions that release energy do not always occur spontaneously

If they did, your book would just catch on fire

The energy needed to get a reaction started is called activation energy

EnzymesWhat roles do enzymes play?

Cells often need help speeding up chemical reactions.

Therefore the produce catalyst

These are substances that speed up the rate of a chemical reaction

Enzymes work by lowering a reactions activation energy

SubstratesSubstrates are the reactants of enzyme-catalyzed reactions

Activation SiteActivation sites are the places on enzymes where substrates bind.

This site is so precise to the substrate that active sites are called lock and key sites

Test time