Cell Unit Lecture V Enzymes and Macromolecules

Biology Standards Covered 1b ~ students know enzymes are proteins that catalyze biochemical reactions without altering the reaction equilibrium and the activities of enzymes depend on temperature, ionic conditions, and the pH of the surroundings 1b ~ students know enzymes are proteins that catalyze biochemical reactions without altering the reaction equilibrium and the activities of enzymes depend on temperature, ionic conditions, and the pH of the surroundings 1h ~ students know most macromolecules (polysaccharides, nucleic acids, proteins, and lipids) in cells and organisms are synthesized from a small collection of simple precursors (monomers & polymers) 1h ~ students know most macromolecules (polysaccharides, nucleic acids, proteins, and lipids) in cells and organisms are synthesized from a small collection of simple precursors (monomers & polymers)

Standards translated 1b ~ an enzyme is a specialized protein that makes a reaction happen or increases the rate of a reaction. Enzymes are affected by pH (acidity), temperature, and salty conditions. 1b ~ an enzyme is a specialized protein that makes a reaction happen or increases the rate of a reaction. Enzymes are affected by pH (acidity), temperature, and salty conditions. 1h ~ Most macromolecules (polymers) are made in cells from a small collection of simple molecules (monomers) 1h ~ Most macromolecules (polymers) are made in cells from a small collection of simple molecules (monomers) This is like a Lego house (polymer) made up of individual Legos (monomers) This is like a Lego house (polymer) made up of individual Legos (monomers)

Carbon Based Molecules All living things are made up of a collection of atoms and molecules that work together to support life All living things are made up of a collection of atoms and molecules that work together to support life Nearly all living things on planet Earth are supported by one atom, an atom of Carbon Nearly all living things on planet Earth are supported by one atom, an atom of Carbon There are Four primary Carbon Based Molecules supporting all life on our planet: There are Four primary Carbon Based Molecules supporting all life on our planet: Carbohydrates ~ sugars Carbohydrates ~ sugars Lipids ~ fats Lipids ~ fats Proteins ~ amino acid chain (polypeptide) Proteins ~ amino acid chain (polypeptide) Nucleic acids ~ DNA, RNA, & ATP Nucleic acids ~ DNA, RNA, & ATP

Carbon Based Molecules Carbon is the most important element in living systems Carbon is the most important element in living systems It has: It has: 6 Protons 6 Protons 6 electrons 6 electrons 6 Neutrons 6 Neutrons Mass of amu Mass of amu It bonds in four directions and can form double bonds It bonds in four directions and can form double bonds

Carbon Based Molecules Carbon based molecules can be small and they can be very large. Carbon based molecules can be small and they can be very large. The smallest are called monomers and usually consist of one carbon ring or molecule The smallest are called monomers and usually consist of one carbon ring or molecule Larger carbon based molecules are made up of many monomers to form a polymer Larger carbon based molecules are made up of many monomers to form a polymer Mono = one Mono = one Poly = many Poly = many

Carbon Based Molecules Carbohydrates as carbon based molecules Carbohydrates as carbon based molecules Also known as “sugars” Also known as “sugars” Made up of three elements Made up of three elements Carbon Carbon Hydrogen Hydrogen Oxygen Oxygen A couple of the simplest carbohydrates are fructose and glucose A couple of the simplest carbohydrates are fructose and glucose These are single carbon ring molecules that provide energy for cellular respiration These are single carbon ring molecules that provide energy for cellular respiration

Carbohydrates can be a simple sugar like Glucose or many Glucose monomers linked together Carbohydrates can be a simple sugar like Glucose or many Glucose monomers linked together A Disaccharide is a sugar that has two Glucose monomers A Disaccharide is a sugar that has two Glucose monomers The most common disaccharide is sucrose The most common disaccharide is sucrose Carbon Based Molecules

Polysaccharides are many Glucose monomers linked together Polysaccharides are many Glucose monomers linked together Starch ~ a polysaccharide sugar made by plants to store energy Starch ~ a polysaccharide sugar made by plants to store energy Cellulose ~ a polysaccharide made by plants to form cell walls Cellulose ~ a polysaccharide made by plants to form cell walls Glycogen ~ a polysaccharide made by animals to store sugar for energy (usually in the liver) Glycogen ~ a polysaccharide made by animals to store sugar for energy (usually in the liver) Carbon Based Molecules

Good Carbs & Bad Carbs

Lipids are an important carbon based molecule that can be broken down into energy for the cell and function as part of the cell’s structure Lipids are an important carbon based molecule that can be broken down into energy for the cell and function as part of the cell’s structure They include fats, oils, and cholesterol They include fats, oils, and cholesterol They are non-polar and repel polar substances like water They are non-polar and repel polar substances like water Carbon Based Molecules

A phospholipid having a phosphate head and two fatty- acid tails is a monomer of the polymer known as the cell membrane A phospholipid having a phosphate head and two fatty- acid tails is a monomer of the polymer known as the cell membrane The phosphate head of the phospholipid attracts water because it is polar while the fatty-acid tails repel it as it passes through the membrane The phosphate head of the phospholipid attracts water because it is polar while the fatty-acid tails repel it as it passes through the membrane Carbon Based Molecules

Lipids store a huge amount of energy in their fatty-acid tails Lipids store a huge amount of energy in their fatty-acid tails A lipid is saturated if the Carbon chain is loaded with Hydrogen atoms A lipid is saturated if the Carbon chain is loaded with Hydrogen atoms A lipid is unsaturated if there are a few or more double bonds between Carbons making it “kink” A lipid is unsaturated if there are a few or more double bonds between Carbons making it “kink” Carbon Based Molecules

Proteins are another important carbon-based molecule made up of several dozen to thousands of amino acids Proteins are another important carbon-based molecule made up of several dozen to thousands of amino acids An amino acid chain is also known as a polypeptide chain because of its many peptide bonds holding the amino acids together An amino acid chain is also known as a polypeptide chain because of its many peptide bonds holding the amino acids together Carbon Based Molecules

Each amino acid is made up of the same functional groups except for one R – Group Each amino acid is made up of the same functional groups except for one R – Group Amino group Amino group Carboxyl group Carboxyl group Hydrogen & base Carbon Hydrogen & base Carbon Unique R Group Unique R Group Amino acids are monomers while a protein is the polymer Amino acids are monomers while a protein is the polymer Carbon Based Molecules

Nucleic acids are the fourth Carbon based molecule Nucleic acids are the fourth Carbon based molecule They are all made up of monomers called nucleotides They are all made up of monomers called nucleotides DNA, RNA, and ATP are nucleic acids that are found in all living organisms DNA, RNA, and ATP are nucleic acids that are found in all living organisms ATP pictured here has 3 phosphates bonded to a 5- Carbon sugar and a Nitrogen base ATP pictured here has 3 phosphates bonded to a 5- Carbon sugar and a Nitrogen base Carbon Based Molecules

Enzymes the special protein An enzyme is a protein polymer that is made up of many amino acid monomers An enzyme is a protein polymer that is made up of many amino acid monomers Cells use enzymes to catalyze biochemical reactions Cells use enzymes to catalyze biochemical reactions To “make them happen” To “make them happen” To “speed up reactions” To “speed up reactions” An enzyme has a unique 3-dimensional shape that defines the role/job that it performs An enzyme has a unique 3-dimensional shape that defines the role/job that it performs An enzymes shape is maintained by being in the right temperature, pH (acidity), and ionic conditions An enzymes shape is maintained by being in the right temperature, pH (acidity), and ionic conditions

Chemical Reactions Chemical Reactions Reactants  Products Reactants  Products Water + Carbon Dioxide  Glucose + Oxygen + Water Water + Carbon Dioxide  Glucose + Oxygen + Water Activation energy is the “energy required to start a chemical reaction” Activation energy is the “energy required to start a chemical reaction” Think of pushing a ball to the top of a small hill so that it can roll down a very steep slope on the other side Think of pushing a ball to the top of a small hill so that it can roll down a very steep slope on the other side The energy it took to push the ball to the top of the hill is the activation energy The energy it took to push the ball to the top of the hill is the activation energy Enzymes often lower activation energies Enzymes often lower activation energies Enzymes the special protein

When enzymes are present, the breakdown of Glucose happens easier  When enzymes are present, the breakdown of Glucose happens easier  Enzymes the special protein

pH is the “percent Hydrogen” of a solution pH is the “percent Hydrogen” of a solution Also known as “acidity” Also known as “acidity” The scale is based on Powers of 10 and goes from 0  14 with Zero being the MOST Acidic and 14 being the MOST Basic The scale is based on Powers of 10 and goes from 0  14 with Zero being the MOST Acidic and 14 being the MOST Basic Enzymes the special protein

An enzyme protein has an active site where a substrate molecule attaches An enzyme protein has an active site where a substrate molecule attaches This makes it possible for a chemical reaction to occur and the enzyme acts as a catalyst This makes it possible for a chemical reaction to occur and the enzyme acts as a catalyst Enzymes the special protein

Enzymes are often referred to as having a “lock and key” model Enzymes are often referred to as having a “lock and key” model Enzymes are affected by temperature and as temp. increases, enzyme activity increases Enzymes are affected by temperature and as temp. increases, enzyme activity increases Enzymes the special protein