Unit 3 Biochemistry

Let’s start with some chemistry background: . ATOMS are the smallest units of an element

Element A substance that cannot be broken down into simpler substances by chemical means. An element is composed of atoms that have the same atomic number

MOLECULE A molecule is formed when two or more atoms covalently bond together chemically. Ex: O2 (oxygen gas), H2O (water), CO2(Carbon dioxide), C6H12O6(glucose), O2

Molecules undergo Chemical Reactions When one or more substances is changed into a new substance by breaking and forming new bonds Energy is absorbed or released, supplying energy for the organism. Ex. 2 H2 + O2 2 H2O (Reactants) (Products)

Biochemistry The Chemistry of Biology Let’s start with the Energy fact #1 Energy can not be created or destroyed in a chemical reaction; it’s just changed!!!

Think about the chemicals we use to power our world: 1. How do we get energy from fossil fuels? A: fossil fuels are Hydro-Carbons

These long chains of carbon and hydrogen bonds will release energy when that bond is broken. Q1. Which of the compounds stores the most energy? Q2. Plastic, motor oil, diesel, or gasoline? Q3. Which has the most stored bond energy?

How do we get energy? (We are not fueled by hydrocarbons) How do living organisms get energy to function? Where do you think this energy originates?

What is the only process that can take inorganic carbon from the atmosphere(CO2) and turn it into an organic fuel molecule that living organisms can use? C6H12O6 (glucose)

Photosynthesis!!!! Yes! A CHEMICAL reaction converts CO2 and H2O into C6H12O6 using the energy (wavelength energy) of the sun!!!

How do we get Energy from food? Everything you eat is composed of chemical molecules. This all originates with plant life through photosynthesis.

There are 4 main molecules found in living things that fuel our life. Carbohydrates: sugar, starch, cellulose molecules that end in (ose) Proteins: Amino acids, Enzymes, Antibodies Lipids: Fats, Phospholipid membranes, fats, Nucleic Acids: DNA, RNA, ATP

Simple (single)Molecules form into MACROMOLECULES Monomer  simple building block Polymer  large complex molecule made of many monomers Polymers are made from monomers

Carbohydrates Group of chemicals that includes sugars, starch and cellulose. 1. Used for short term energy storage. 2. Simple sugars are the easiest substance for your body to breakdown. 3. Stored as glycogen, in muscles if not used quickly

Carbohydrates 3 Types: Monosaccharide (one sugar) (monomer) glucose 2. Disaccharide (two sugars) (polymer) sucrose 3. Polysaccharide (many sugars) Ex: Plant starch or animal glycogen

Carbohydrates ALWAYS: Consist of C, H, and O in a 1:2:1 ratio Example: Glucose (C 6 H 12 O 6) Sucrose ( C12H24O12) Which molecule below is a carbohydrate? A. C24H16O32 B. C8H16O32 C. C16H32O16

Monosaccharides one monomer (“building block”) of sugar simplest carbohydrate Example: Glucose (C 6 H 12 O 6)

Disaccharides Two monosaccharides covalently bonded Examples: sucrose lactose fructose glucose glucose galactose

Polysaccharides Cellulose Starch Potato is a plant stored starch Straight or branched chains of many sugar monomers Starch Potato is a plant stored starch Glycogen Animals store glycogen, which is produced in the liver or muscle Cellulose Cellulose is a non-digestible carbohydrate, the most abundant molecules on earth. Ex: Pencils, paper, wood.

Proteins Large complex molecules composed of smaller units(monomers) called Amino Acids (AA) There are 20 different AA combinations of different amino acids produce different proteins. All 20 amino acids have a: NH3 group (amine group) a COOH (caryboxylic group) And a R (variable group)

Protein molecules twist and fold into 3 Dimensional structures that carryout many different functions.

Proteins can function as: Enzymes: help speed chemical reactions Antibodies: Attach to bacteria, cancer cells and other antigens and kill it. Connective tissue Muscle tissue Cell signalers………and many other things Proteins run your body in soo many ways!! We will focus on Proteins as Enzymes

Why Are Enzymes So Important? Nearly all chemical reactions in biological cells need enzymes to make the reaction occur fast enough to support life. From the Virtual Cell Biology Classroom on ScienceProfOnline.com Image: Jumping rope, Meagan E. Klein

What are Enzymes? They are : Proteins that act as catalysts: Catalysts speed up the rate of chemical reactions by binding molecules together or helping to pull molecules apart.

Enzymes Facts Most enzymes end in “ase” Each enzyme is VERY specific to its substrate. One enzyme for one substrate! Lactase breaks down Lactose What breaks down fructose?_______ What breaks down Sucrose?_______ Enzymes are reusable and do not get destroyed in the reaction. Enzymes break molecules apart and also build them together!!!

Enzymes speeds up chemical reactions by lowering activation energy. Activation Energy is the Energy needed to make reaction happen.

How Do Enzymes Work? Enzymes & substrates fit together like a Lock & Key 1) Enzymes attach to a substrate (the molecule it is working on) at the Active Site of the enzyme. 2) Chemical bonds are either formed or broken in the substrate 3) Products of substrate are released 4) Enzyme is now free to bind to another substrate, and continues this process until the substrate is all broken down

Enzymes are fragile. They can be destroyed by certain situations. 1. High Temperatures The high temperatures change the 3 dimensional shape of the enzyme, This is called “Denaturing” Why high fevers can kill us Cooking veggies is bad because we lose good enzymes 2. Other factors that affect enzyme function: pH (acidity or basicity), Substrate Concentration, And Enzyme Concentration STRUCTURE=FUNCTION If the structure changes by denaturing, will it still function correctly?

Lipids Fats, oils, waxes, phospholipids, and steroids. Used for long term energy storage Fats act as an insulator Waxes (plants) act as a water repellant Keep leaves from drying out Make ducks feathers waterproof

Fats are long chains of Hydrocarbons (CH)= Fatty Acids bonded to molecules of glycerol. Many of these can come together to form very large structures but they are NOT polymers. They are not chemically combined. ….but they do “stick” together. We have 2 kinds of FATS The fatty acid chains contain only single bonds C-C-C-C Found in animal products (milk, beef fat, bacon fat) Solid at room temp (butter) Saturated fats

UnSaturated Fats Contain one or more Carbon double bonds C-C=C=C Found in plant products (olive oil) Liquid at room temp

Another Extremely important Lipid is Phospholipids Lipids that form membranes of the cell Helps control movement in and out of the cell

Steroids Made up of 4 carbon rings EX: Cholesterol, Lipids with no fatty acids Made up of 4 carbon rings EX: Cholesterol, EX: Many hormones are types of steroids like testosterone, estrogen Steroid back bone

Nucleic Acids Large/Long polymers of nucleotides that contain hereditary information: DNA, RNA Nucleotides are the monomers of Nucleic acids Chemical Make-up of a nucleotide Phosphate: PO4 Sugar: C5H10O5 Nitrogen base: C5H5N5

Nucleotides chemically bond together to make polymers of DNA and RNA One Very important single nucleotide is called ATP. This is an energy storage molecule. It provides energy for other reactions By having a phosphate chopped off and then another added. .

1. The 4 major biomolecules are: 2. The three that form polymers are: 3. The one biomolecule that does not form polymers is: 4. The monomer of a carbohydrate is: 5. The monomer of a protein is: 6. The 2 molecules that bond to create Fats are: The monomers of Nucleic Acids are: We ingest molecules of these 4 categories and break them down and use the parts to create other molecules our body needs. What type of molecule helps to speed these reaction? What process starts the entire chain of events that leads to life?