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The stuff that living things are made of…
Biomolecules The stuff that living things are made of…
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What are Biomolecules? Chemical compound that provides physical structure and bring about movement, energy use, and other cellular functions. They make up living things. These molecules are made mostly of the elements Carbon (C) , Hydrogen (H), and Oxygen (O). IF you do not have at least one of each of these elements you are an inorganic molecule.
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The 4 basic Biomolecule Classes
Carbohydrates Lipids Proteins Nucleic Acids
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Sweet, Sweet Carbohydrates
Carbohydrate is a fancy way of saying "sugar." Carbohydrates can be very small (glucose) or very large molecules (cellulose), but they are still considered sugars. Always end in “-ose” Function: Sugars provide living things with energy and act as substances used for structure. Some examples of structural uses might be the shell of a crab (chitin) or the stem of a plant (cellulose).
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Simplest Sugar: Glucose
What about the simplest of sugars? A sugar called glucose is the most important monomer (ONE – molecule) on Earth. Glucose (C6H12O6) is created by photosynthesis and used in cellular respiration. When you think of table sugar, like the kind in candy, it is actually a dimer. (Two – molecules) dimer table sugar AKA Sucrose
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Examples of complex carbohydrates used for structure and protection
Cellulose. Cellulose is found in plants. Cellulose is in wood and the cell walls of plants. You know that shirt you're wearing? If it is made of cotton, that's cellulose, too! Humans can not digest cellulose (think corn it goes out looking like it came in) polymer with many glucose monomer units
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Examples of complex carbohydrates used for structure and protection
Complex carbohydrates are also used in the shells (chitin) of crustaceans, such as crabs and lobsters. The shells are solid, protective structures that need to be molted (left behind) when the crustacean begins to grow. It is very inflexible but very resistant to damage. If you know the way crabs are cooked, you know that the crab meat cooks on the inside of the shells when it is boiled. There is no damage to the shells at the temperature of boiling water (H2O at 100oC). Chitin is also a polymer
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Examples of carbohydrate:
Monomer dimer polymer Deoxyribose glucose units joined (plant matter humans can digest) glucose units every other opposite direction (plant matter humans can’t digest) glucose units split off different directions (humans use sugar for storage)
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Lipids Lipids are large molecules that do not dissolve in water because they are NON POLAR. Lipids are fats and used to make steroids and waxes. So, if you pick out some earwax, that's a lipid!
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Lipids Lipids have a lot of energy stored up in their molecular bonds. That's why the human body stores fat (lipids) as an energy source. When you have extra sugars in your system, your body converts them into fats. When it needs extra fuel, your body breaks down the fat and uses the energy.
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Lipids (saturated vs unsaturated)
Single bonds At least 1 double Bonds: Bonds: Butter, coconut oil, whole milk, meat, peanut, margarine, cheese, veg oil ,fried foods frozen dinners: Found in: Avocado, soybean, canola oil, fish, walnuts, red meats Melting point: high Low Physical state at room temp: Solid Liquid
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Lipids Waxes are used to coat and protect things in nature. It can be used for structures, such as the bees' honeycombs. Plants use wax to stop evaporation of water from their leaves. Help to form membranes (like a fence) Function of lipids = energy storage and protection and communication between cells Example : Cell membrane
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Steroids a type of lipid
Steroids are found in animals within something called hormones. The basis of a steroid molecule is a four-ring structure You may have heard of steroids in the news. Many bodybuilders and athletes have used anabolic steroids to build muscle mass. The steroids make their bodies add more muscle than they would normally be able to. Those anabolic steroids help bodybuilders wind up stronger and bulkier (but not faster) but with HUGE side effects: internal organ failure, death, extreme emotional responses etc. Steroids are also used in necessary medicines. Some help people with acne, while others are used as muscle relaxers for injuries.
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Before proteins are amino acids
Amino acids are used in every cell of your body to build the proteins you need to survive. All organisms need proteins Even though scientists have discovered over 50 amino acids, only 20 are used to make proteins in your body. The different combinations of those twenty are used to make all of the proteins in your body (over 2 million). Amino acids bond together to make long chains. Those long chains of amino acids are proteins.
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20 Amino Acids that Humans use to make over 2 million different proteins
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Proteins Function: A compound used by living things to build and repair body parts and regulate body activities. Made up of Amino Acids Special proteins Are Enzymes and can speed up chemical reactions Proteins form skin, hair, and horns.
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Proteins fold up … Primary Structure A chain of amino acids
Primary Structure Amino acid chain Primary Structure A chain of amino acids Secondary Structure The original chain begins to twist. It's as if you take a piece of string and twist one end. It slowly begins to curl up. In the amino acid chain, each of the amino acids interacts with the others and it twists like a corkscrew (alpha helix) or it takes the shape of a folded sheet (beta sheet).
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Proteins fold up … Tertiary Makes Step Three
The amino acid chains fold more and bond together. Quaternary Is Fourth and Final In the quaternary structure, several tertiary amino acid chains bond together A famous protein blobs is hemoglobin in human red blood cells which carry's oxygen around our body. Quaternary Structure Amino acid chain Even though a protein can be very complex, it is basically a long chain of amino acid all twisted around like a knot.
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If the shape gets messed up (denatured) it wont work
The shape of a protein determines its FUNCTION (job) If the shape gets messed up (denatured) it wont work Think of it like a wheel of a bike, if the wheel gets bent (denatured) the bike wont function the same Reminder: function follows structure, structure follows function
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Why is this important? The quaternary shape of a protein will determine its job/function… if it gets messed up (denatured) it will no longer be able to function… Proteins are required to do almost anything and everything in your body so if you mess up a protein you may lose a important body function
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What can denature a protein?
Strong acids and bases Heavy metals Heat (temperature)and Radiation Detergents and solvents Real life example: When food is cooked, some of its proteins become denatured. This is why boiled eggs become hard and cooked meat becomes firm. This is ok to eat but if this happens in the body it could kill an organism
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Nucleic Acids They are called nucleic acids because scientists first found them in the nucleus of cells. Now that we have better equipment, nucleic acids have been found in mitochondria, chloroplasts, and cells that have no nucleus, such as bacteria and viruses. Very large and complex molecules. Function: Store and transfer important information in the cell. DNA, RNA, rRNA, mRNA, and tRNA. DNA stands for deoxyribonucleic acid. RNA stands for ribonucleic acid.
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Nucleic Acids Nucleic acids are made up of a sugar, base, and a phosphate group AKA nucleotide. There are 5 possible bases: DNA sugar is Deoxyribose RNA sugar is ribose
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Identify the following as lipid, carbohydrate, protein or nucleic acid
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Crash course Time Biological Molecules - You Are What You Eat: Crash Course Biology #3
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Enzymes: “Helper” Protein molecules
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Enzymes Catalysts that lower the Activation Energy They are SPECIFIC
SPEED UP Chemical Reactions They are SPECIFIC They are NOT CONSUMED [Recyclable] Have an ACTIVE SITE-”Lock & Key” Model Are affected by pH, TEMPERATURE and SHAPE
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Before Enzymes … we need to review Chemical Reactions (RXN)
A process that changes one set of substances into a new set of substances. (chemical change) Process: Bonds are broken and new bonds are made. AB + CD -----> AD + BC Reactants -----> Products Products Reactants B C A B C D D A + + ENZYME
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Chemical reactions of life
Processes of life building molecules synthesis breaking down molecules digestion + +
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What are enzymes… Activation energy is… (activation = start)
Most are specialized proteins that assist in chemical RXN by lowering activation energy Activation energy is… (activation = start) The energy it takes for a Reaction to Start Amount of energy it takes to get the ball rolling = activation energy
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Enzymes are catalysts Catalysts = something that speeds up a chemical RXN without being destroyed or changed
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What do enzymes help you do?
Without enzymes it would take you years to digest a simple apple They help you .. Digest your food Breathe Move your arm, leg, etc. DO EVERYTHING inside and outside of your cells!!! How important are enzymes? all chemical reactions in living organisms require enzymes to work
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What do they look like Enzyme Active site Substrate
real life representation Enzyme proteins that speed up chemical reactions without being changed itself Active site where the substrate binds to the enzyme Substrate Substance that enzymes act upon 3D real life representation Animation
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Enzymes are specific they will only work on 1 type of substrate
Enzymes are named for the substrate they catalyze Always ends in –ase (ok almost always) Sucrase works on sucrose----Lactase works on lactose Protease breaks down proteins----Lipase breaks down fats DNA polymerase builds DNA Enzymes are reusable too: enzyme is the same before and after the RXN
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A case of missing enzymes
You may have heard of people who are lactose intolerant, or you may suffer from this problem yourself. The intestinal cells of lactose-intolerant people do not produce lactase, the enzyme needed to break down lactose This problem shows how the lack of just one enzyme in the human body can lead to problems. Imagine if you were missing 3 or 5 or 10 – you may not even be capable of living!!
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A case of missing enzymes
With lactase enzyme when the enzyme is present it facilitates the break down of lactose into glucose which can be used by the body for energy Lactose
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Shape is critical Every enzyme needs to be the right shape for the job
If the shape gets messed up then the enzyme stops working Denatured protein – a protein that has lost its ability to function because it has lost its shape Remember enzymes are required for all chemical reactions in living organisms
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Lock and Key model shape of protein allows enzyme & substrate to fit
specific enzyme for each specific RXN Just like there is a specific key for a lock to a door
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What can mess up an enzymes shape…
Amino acid sequence Temperature pH
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Reminder- an enzyme is a special protein a protein is a chain of amino acids that have a primary, secondary, tertiary, and quaternary shape. Shape often determines function Think back to example of a wheel …
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Messing up an enzyme- Order of amino acids
Wrong order = wrong shape = can’t do its job! folded protein chain of amino acids DNA right shape! folded protein chain of amino acids DNA wrong shape!
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Temperature Optimum temperature - is different for each protein, however… if an enzyme’s job is to work in a human body then what temperature do you think it will work best at… Human body temp 37.0 C ° (98.6 °F) If the temp gets to high or too low… The protein becomes denatured = unfolds = lost shape = does not work
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Optimal temp for enzymes in human
human enzymes 37° reaction rate temperature Question: Dogs average temp is 103 °F what temp do you think their proteins work best at?
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pH - "power of hydrogen" Again different enzymes work best at different pH Stomach enzymes require an acidic environment around 2 pH Intestine enzymes require a alkaline (base) environment around 8 pH Each enzyme in an organism has its own pH requirement. If the pH changes, it may no longer be able to function because it will denature…
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pH stomach pepsin intestines trypsin reaction rate 1 2 3 4 5 6 7 8 9 10 11 12 13 14 pH Question: your blood has a pH of 7.4 what pH do you think blood proteins work best at?
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For enzymes…What matters?
Shape!! Shape!! If it denatures it loses its ability to work!!
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Enzyme note questions What is an enzyme? What is activation energy?
How do enzymes work ? (what exactly does it do….) Enzymes are _____________ that speeds up a chemical reaction by decreasing _______________ ___________ Can any enzyme act as a catalyst for any chemical reaction? Why or Why not? What does it mean when an enzyme denatures? A chemical reaction is where __________ are broken or made or rearranged.
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