Chemistry in Biology A VERY Brief Overview of Chemistry Chapter 6.2 – Clicker Questions!

Words in Bold Pink Those are your vocabulary words… Please high-light them!!!

Element Element: Substance consisting entirely of one type of atom. Examples: Carbon, Hydrogen, Oxygen

Subscript A subscript is a small lowered number after a symbol for an element. H 2 O– the 2 is lowered and considered a subscript. The 2 indicates how many atoms of the element are present in that compound.

Chemical Compounds Compound: A substance formed by the chemical combination of 2 or more elements in definite proportions. Examples: H 2 O (water) NaCl (Salt) C 6 H 12 O 6 (Sugar)

Chemical Formula States how many atoms are in each molecule. How many carbon atoms are in C 6 H 12 O 6 ? How many hydrogen atoms? How many oxygen atoms? Click for answers

Chemical Equations Let’s say I give you a chemical equation like— CO 2 + H 2 O C 6 H 12 O 6 + O 2 What are the names of these compounds? Could you tell me which side are the reactants and which side are the products? REACTANTSPRODUCTS Carbon dioxide Water Sugar/glucose Oxygen Click for answers

Elements in the Human Body Oxygen – 65% Carbon – 18.5% Hydrogen – 9.5% Nitrogen – 3.3% All of these equal 96.3%. The other 4% are trace elements: Calcium (1.5), Phosphorous (1.0), Potassium (0.4), & others. Water Most abundant element in our body Most abundant compound in our body Click for animation

Clicker Question #1 Which of the following is an element? a. Carbon dioxide b. Methane c. Oxygen d. Water

Clicker Question #2 How many atoms are in: NH 3 a. 1 b. 2 c. 3 d. 4

Clicker Question #3 Which of the following are the reactants? CH O 2 CO H 2 O a. CH O 2 b. CO H 2 O c. CH H 2 O d. None of the above

Solvent-Solute Water is the greatest solvent in the world! Solvent means to dissolve, or a dissolving agent. WATER is a SOLVENT! Solute is what is to be dissolved. Sugar and salt are solutes and they dissolve in water.

pH pH : The measure of concentration of H + in a solution. Acid : Substance that release hydrogen ions (H+) when dissolved in water. Base : Substance that releases hydroxide ions (OH-) when dissolved in water.

pH Scale The pH scale measures how acidic or basic a substance is. It ranges from 0 to 14 A pH of 7 is neutral A pH less than 7 is acidic A pH greater than 7 is basic

Acids Acids taste sour Strong Acids are dangerous and can burn your skin Examples are: Vinegar, stomach acid, and citrus fruits

Bases Solutions containing bases are often called alkaline. Bases taste bitter Bases feel slippery Strong bases are very dangerous and can burn your skin Examples: Lye and ammonia

Oven cleaner Bleach Ammonia solution Soap Sea water Human blood Pure water Milk Normal rainfall Acid rain Tomato juice Lemon juice Stomach acid Neutral Increasingly Basic Increasingly Acidic 14 = Basic 0 = Acidic 7 = Neutral pH Scale

pH Question An ecologist is testing rainwater. She tests rainwater on the south side of town and finds that the pH is 6.2. Then she tests the north side of town and finds that the pH is 6.8. Which is more acidic? 6.2 is correct! Click for answer

Buffers Buffers are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH. (Don’t need to write this) For example, your stomach is upset, so you drink alka seltzer or eat a Rolaids. These are buffers or a mild base to offset the higher stomach acid.

Clicker Question #4 Which of the following is a solute? a. Water b. Sugar c. Vinegar d. Carbon dioxide

Clicker Question #5 Which of the following has the most basic pH? a. 7 b. 7.1 c. 7.5 d. 8

Clicker Question #6 3.1 pH is: a. Acidic b. Basic c. Neutral d. None of the above

Clicker Question #7 Gastric protease works best in which type of pH? a. Neutral b. Basic c. Acidic d. All of the above

Clicker Question #8 Which of the following is a solvent? a. Water b. Sugar c. Vinegar d. Carbon dioxide

Organic Molecules There are 4 organic molecules – Carbohydrates – Lipids – Proteins – Nucleic Acids * These are also called macromolecules

Carbon Compounds includes that consist of Macromolecule Concept Map Macro means LARGE YES, draw this!

Carbohydrates Carbohydrate: Organic compound containing Carbon, Hydrogen, & Oxygen with a ratio of 1:2:1 Carbohydrates are basically sugars and starches. ***Most of an organisms’ energy come from carbohydrates!***

Carbohydrates Continued Monosaccharides are simple sugar molecules. Examples: This is glucose, galactose, sucrose and fructose (sugars). Glucose is 1 : 2 : 1 Many monosaccharides together make up polysaccharides. This is the excess sugar that we store as glycogen that can turn into fat

Carbohydrates Starch – Storage form of sugars

Starch in Plants Cellulose – found in the cell walls of plants

Starch in Animals Glycogen – in humans, glycogen is stored in the liver.

Write these Video Questions & answer them while you watch the video clip. 1. Sugars belong to a class of chemicals called ___. 2. What is glucose made-up of? 3. What is a good example of a very long polymer of glucose called ___. 4. Starches are nothing more than very long chains of ____.

Carbohydrate Video Clip Video

Carbon Compounds includes that consist of Macromolecule Concept Map Macro means LARGE Lets fill in the chart! Carbohydrates Sugars & Starches Major source of energy for the body

Lipids This is FAT. Lipids: these are used to store energy. They are found in cell membranes. Fats, oils, & waxes Also water proofs Video

Saturated & Unsaturated Fats Saturated Fats – Chemical compounds that have a chain of carbon atoms linked together by single bonds. Unsaturated Fats – Chemical compounds that contain carbon-carbon double or triple bonds.

Saturated & Unsaturated Fats

Unsaturated Fats Unsaturated fats tend to be liquid at room temperature due to kinks in the carbon chain resulting from the double or triple bonds. These fats are called oils and are also present in fish and plants.

Saturated Fats Saturated fats tend to be solid at room temperature. Examples are butter, dairy products, and the fat found in meat.

Health Considerations Saturated fats are considered unhealthy in excess because they are known to raise “bad” cholesterol (LDL), leading to heart disease, stroke, and other problems. Unsaturated fats are considered healthier because they raise “good” cholesterol (HDL).

Carbon Compounds includes that consist of Macromolecule Concept Map Macro means LARGE Lets fill in the chart! Carbohydrates Sugars & Starches Major source of energy for the body Lipids Fats & Oils Stores energy & water proofs

Nucleic Acids Made up of Carbon, Hydrogen, Oxygen, Nitrogen, & Phosphorus Nucleic acids store and transmit hereditary or genetic information.

Nucleic Acids Continued Nucleotides consist of a 5 carbon sugar, a phosphate group and a nitrogen base. 2 types: Deoxyribonucleic Acid (DNA) & Ribonucleic Acid (RNA)

Video Questions: 1. Nucleic acids are made up of long chains of subunits called ____. 2. Chromosomes contain huge molecules called deoxyribonucleic acid also known as ___.

Nucleic Acids Video Clip Video

Carbon Compounds includes that consist of Macromolecule Concept Map Macro means LARGE Lets fill in the chart! Carbohydrates Sugars & Starches Major source of energy for the body Lipids Fats & Oils Stores energy & water proofs Nucleic Acids Nucleotides Stores & Transmits Genetic Info

Clicker Question #9 Which of the following is NOT a macromolecule? a. Carbohydrate b. Lipid c. Salt d. Nucleic acid

Clicker Question #10 Which of the following foods is NOT an example of a carbohydrate? a. Sugar b. Potatoes c. Bread d. Meat

Clicker Question #11 Genetic material is made with this macromolecule: a. Nucleic acid b. Lipid c. Protein d. Carbohydrate

Clicker Question #12 Which of the following is NOT a sugar? a. Glucose b. Sucrose c. Lactose d. Pepsin

Proteins Proteins are composed of smaller units called amino acids. Amino Acids : Are small compounds that are made of carbon, nitrogen, oxygen, and hydrogen.

Proteins Activation Energy : The minimum amount of energy needed for reactants to form products in a chemical reactions.

Proteins A catalyst, as well as an enzyme, is a substance that lowers the activation energy needed to start a chemical reaction. * Catalysts speeds up chemical reactions thousands of times faster.

Proteins Enzymes are biological catalysts that speed up the rate of chemical reactions. * Enzymes are made of proteins. Example: Amylase found in saliva. Amylase speeds up the breakdown of amylose, a substance in starch (in foods). * Most enzymes are specific to 1 reaction

Proteins: How enzymes work Substrate: The reactants that bind to the enzyme. Active Site: The specific location where a substance binds to an enzyme. * The active site and the substrate have complementary shapes (“Lock & Key”) Click on picture to see an animation!

Proteins: How enzymes work Only substrates with the same size and shape as the active site will bind to the enzyme (like puzzle pieces). pH and temperature mainly affect enzyme activity. Click on picture for link

Enzymes Denature – to change the shape of an enzyme so that it no longer works, usually due to a sudden change in pH or temperature

Pepsin : An Enzyme Pepsin is an enzyme in the stomach that begins the digestion of proteins by splitting them into smaller pieces. Pepsin works at a pH level of around 2 which is acidic Antacids are used to neutralize pepsin by increasing the pH level to around 6 or 7

Carbon Compounds includes that consist of Macromolecule Concept Map Macro What does Macro Mean? Lets fill in the chart! Carbohydrates Sugars & Starches Major source of energy for the body Lipids Fats & Oils Stores energy & water proofs Nucleic Acids Nucleotides Stores & Transmits Genetic Info Proteins Amino Acids Growth/ repair & make up enzymes

Clicker Question #13 Enzymes are which type of macromolecule? a. Lipids b. Carbohydrate c. Proteins d. Nucleic Acids

Clicker Question #14 What do enzymes do during a reaction? a. Nothing b. Slows it down c. Speeds it up d. Burns it up

Clicker Question #15 What two conditions change how enzymes work? a. Water & temperature b. Temperature & pH c. Solid & gas d. None of the above

The End

Clicker Question Answers 1. C11. A 2. D12. D 3. B13. C 4. B14. C 5. D15. B 6. A 7. C 8. A 9. C 10. D