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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