520 likes | 621 Views
Chemistry of Life. Ch. 2. If you tear paper in half, and keep tearing the halves into halves, will you always have paper left? What is the smallest unit eventually left?. Some isotopes are radioactive. They are used for determining ages of fossils.
E N D
Chemistry of Life Ch. 2
If you tear paper in half, and keep tearing the halves into halves, will you always have paper left?What is the smallest unit eventually left?
Some isotopes are radioactive. They are used for determining ages of fossils. They are also used to treat cancer or as tracers. Ie. 12C- non radioactive (6p+, 6 neutrons) 14 C- Radioactive (6 p+, 8 neutrons) (protons and electrons stay the same, the neutrons are different. If you add the p+ and neutrons you get 12 or 14.) Isotopes
Do you know the structure of an atom? Do you know how atoms bond? Do you know element symbols? Do you understand how a chemical reaction works? The Basics of Chemistry
Van der Waals- slight attraction between oppositely charges regions of molecules. They can hold large molecules together. Gecko’s feet Hydrogen bonds- an atom of a molecules interacts weakly with a H atom. Holds together N bases on DNA. Weaker Bonds
Sometimes covalent bonds do not share electrons equally. Some atoms in the molecule have a slightly negative charge and others have a slightly positive charge. Water Link Water molecule. NH3 How do you know it’s polar? Polar Molecules (-) O H H (+) (+) .
Cohesion Hydrogen Bonding causes water molecules to stick together, producing surface tension. Adhesion- sticks to something else. Water Expands when it Freezes Ice Floats because it is less dense than the water. Features of Water
Mixture- material composed of two or more elements or compounds that are physically mixed together but not chemically combined. Salt and pepper, sugar and sand, etc. Solution- well mixed mixture. Where all components are evenly distributed. Give an example. Solutions
Suspensions Mixtures of water and non-dissolved materials. Can you give any examples? Common suspensions include sand in water, fine soot or dust in air, and droplets of oil in air.
Can you explain this? Can you give any examples of this? What do you know about pH? 1.5 Most cells have a narrow range of temperature and acidity that they can survive. If there are extreme changes in the environment, they may alter the structure of the protein and the cells function.
Scales of 10. A pH of 4 would have 10x more H+ than a pH of 5. Animated pH scale
H+ OH-
Weak acids and weak bases that react with strong acids or bases to prevent sharp, sudden changes in pH. Control pH to maintain homeostasis. Buffers Hemoglobin (carries oxygen) maintains a stable pH in red blood cells (RBC).
1.4 The work that takes place in the cell is carried out by the different types of molecules it assembles: proteins, lipids, carbohydrates, and nucleic acids.
Carbon C Hydrogen H Nitrogen N Oxygen O Phosphorus P Sulfur S Carbon can join to other carbon atoms in chains and rings to form large complex molecules. 1.6 Cells are made up primarily of a small number of chemical elements
Monomers- 1 unit Polymers- many units The process of joining monomers to make polymers is polymerization. Ex: Sugars make up starch, Amino acids make up proteins, fatty acid chains make up lipids. Monomers vs. Polymers
Carbohydrates are a group of chemicals that include sugars, starches and cellulose. They store energy and provide shape to organism Chemicals in Organisms
Monosaccharides- single sugars Glucose, fructose, galactose Disaccharides- double sugars Sucrose(table sugar), lactose Polysaccharides- many sugars Glycogen, starch Sugars CH2O This is in linear form.
A group of chemicals that include fats, oils, waxes, phospholipids, and steroids. Fats and oils provide long-term energy storage. Waxes repel water. Phospholipids form membranes of cells and control what enters and leaves. Steroids serve structural and control functions in your body. Ie. Cholesterol, sex hormones Lipids Fatty acid chain (lipid) Do you see the hydocarbon chain?
Why would lipids need high energy bonds? 1.10 Macromolecules, such as lipids, also contain high energy bonds. This is unsaturated fat. What do you think unsaturated would look like?
Large, complex molecules composed of many smaller molecules called amino acids. There are 20 amino acids. H H-N-C-C=O H R OH Enzymes are proteins that help control chemical reactions. Proteins Carboxyl group Peptide bond, H20 is lost Amino and carboxyl groups form peptide bonds between them to form a protein. Amino group
Large, complex molecules that contain hereditary or genetic information. DNA- deoxyribonucleic acid RNA- ribonucleic acid Nucleic Acids DNA or RNA? We will learn more about the structure of DNA and RNA in Ch. 7
Photosynthesis Captures energy Chloroplasts in plants 6CO2 + 6H2O C6H12O6 + 6O2 Cellular Respiration Releases energy Mitochondria C6H12O6 + 6O2 6CO2 + 6H2O Photosynthesis vs. Cellular Respiration What do you notice about these two equations? 1.3, 1.4, 1.9, 1.43
Chemical Reactions that release energy often occur spontaneously. (Exothermic) Chemical Reactions that absorb energy will not occur with out a source of energy. (Endothermic ) Activation energy is the energy needed to start a reaction. *Transparency Chemical Reactions
Enzyme-Substrate Complex • All enzymes end in the letters –ase. • Sucrose (substrate) binds to enzyme at active site. • Enzyme is activated and breaks bond between disaccharide. • Glucose and fructose are now monosacchrides. • Enzyme retakes it shape. Tutorial
ATP- Adenosine TriPhosphate When the bonds break energy is released. When bonds form, energy is stored. 1.9 Living and non-living things are composed of compounds. These compounds contain bonds that hold them together. ATP, the energy source in cells, is stored in the bonds. Can you explain this analogy?
ATP (adenosine triphosphate) is where energy is stored when it is released form nutrients. What does it look like? N base: adenine 5’ C sugar: Ribose 3 Phosphate (PO4) groups ADP (adenosine diphosphate) How many phosphates are there? What do you think will happen when you add another phosphate? ATP
Energy is stored in bonds. When you break bonds you release energy and when you make bonds you store energy. ADP + Pi + Energy ATP Are we storing or releasing energy? ATP ADP + Pi + Energy Storing or releasing energy? Forming and Breaking Down ATP Pi + Energy ATP ADP Pi + Energy
Energy is the ability to do work. Cells get energy from food and break down nutrients to get stored energy in the bonds between atoms. Energy in the Cell
To grow and develop, the cells of organisms must make many new carbohydrates, proteins, and lipids. In order for your body to repair itself, chemical reactions are needed to produce new cells to replace the damaged ones. Growth and Repair