The study of life. All organisms share certain properties. All organisms do these things at some point during their life.

Transcription

1 Biochemistry

2 The study of life All organisms share certain properties. Cellular organization Homeostasis Metabolism Responsiveness Reproduction Heredity Growth All organisms do these things at some point during their life.

3 Cellular Organization A cell is a highly organized, tiny structure that is enclosed in a thin covering called a membrane. The cell is the basic structure of all living things.

4 Homeostasis The maintenance of stable internal conditions in spite of changes in the external environment is called homeostasis. All living organisms must maintain a stable internal environment.

5 Metabolism Metabolism is the sum of all of the chemical reactions carried out in an organism. What provides the energy for life on earth? The sun

6 Responsiveness Plants and animals must be responsive to their environment to cope with changes that occur. The natural world is very difficult and dangerous. Organisms must be willing to respond to changes that occur.

7 Reproduction Because no organism lives forever, reproduction is an essential part of life. The goal of all organisms is to reproduce! Those organisms that have the ability to survive and reproduce avoid extinction.

8 Heredity When an organism reproduces, it passes on its own traits to its offspring. Heredity is the reason that children tend to look similar to their parents.

9 Growth All living organisms grow. Some grow for only a short period of time, but other organisms grow for thousands of years.

10 Are viruses such as swine flu and HIV living things? Cell theory: All living things are made up of cells. Cells are the basic unit of all life. Each cell has a specific job. All cells come from existing cells! Requirements to be considered living: Cellular organization Homeostasis Metabolism Responsiveness Reproduction Heredity Growth

11 So are viruses alive? So, are viruses alive: NO A Virus is not made of cells, so they are not living organisms! Viruses require other cells (like YOURS) for survival.

12 Viruses At this point in time, viruses are still considered to be non-living (different from dead these things have never been nor ever will be living). For the purposes of this class, viruses are non-living. This is up for change though, as the scientific community re-defines what constitutes living In the next 10 years, viruses could be considered a living thing!!

13 After learning about viruses in Biology class, Sam decides to have his cat vaccinated against feline leukemia virus. According to cell theory, are viruses, such as feline leukemia, considered living things? Yes, because they can reproduce Yes, because they are composed of cells No, because they cannot adapt to their environment No, because they are not composed of cells

14 Ethan wants to determine whether temperature affects the rate at which mold grows on bread. He puts one piece of bread inside a covered petri dish in the refrigerator. To determine whether temperature affects the growth of mold, Ethan should place another piece of bread into a petri dish: Leave the dish uncovered, and place the dish in the refrigerator Cover the dish, and place the dish in the refrigerator Leave the dish uncovered, and place the dish in a dark, room temperature cabinet Cover the dish, and place the dish in a dark, room temperature cabinet.

15 What is the best definition of a scientific theory? An explanation of how and why a natural phenomenon behaves the way it does A description of an invariable relationship that exists in nature A speculation or guess about how nature works An unproven fact

16 A little Chemistry! Matter: anything that has mass and takes up space. To understand how living things work and interact, you must first understand the structure of matter. Matter is made of small particles called atoms. Atom: the smallest unit of matter that cannot be broken down any smaller.

17 Atomic Structure Atoms are made of THREE types of particles Protons (+) positive charge Electrons (-) negative charge Neutrons have no charge Protons and Neutrons make up the core (nucleus) of the atom, while electrons move around the nucleus in the electron cloud.

18 Atomic Structure and the Periodic Table Atomic number = # of protons In a neutrally charged atom, the # protons = # electrons In an ion (a charged particle), the # electrons will change More electrons than protons = negative ion Fewer electrons than protons = positive ion Atomic mass number = # protons + # neutrons

19 Elements Elements: substance made up of atoms. For example each atom of the element carbon has 6 protons (+). To be balanced, how many electrons (-) should carbon have? The atomic mass of carbon is 12. How many neutrons should carbon have? If an element is made of atoms that have different numbers of neutrons, then they are called isotopes.

20 Give it a try fill in the table! Element Atomic # Atomic Mass ** Carbon # Protons # Neutrons #Electrons Hydrogen Oxygen Phosphorus Nitrogen ** Round the number for the atomic mass given in the periodic table to the nearest WHOLE NUMBER. There are no ions nor isotopes in this activity.

21 A quick word on bonding Covalent bond: a bond where two atoms share valence electrons Commonly seen in bonding between atoms in biomolecules Ionic bond: a bond where one atom completely transfers its valence electrons to another atom Hydrogen bond: a bond where a molecule has slightly charged poles (making it a polar compound) and can form slight electrostatic bonds with other polar molecules

22 The Chemistry of Life! The parts of a cell are made up of large molecules called biomolecules. The basic units of most biomolecules contain atoms of CARBON. Carbon has 4 valence electrons so they can bond covalently. Carbon atoms in these chains and rings can connect with other atoms of other elements to form the basic unit of most biomolecules.

23 Carbohydrates Carbohydrates are molecules made of sugar. A sugar contains Carbon (C), Hydrogen (H), and Oxygen (O) in a ratio of 1:2:1. Examples of sugars (NOTE: all names end in ose): Glucose Sucrose Fructose Monosaccharide (simple sugar) Disaccharide (this is table sugar) Two sugars can be linked together to form a disaccharide. Cells use carbohydrates for sources of energy, structural material, and cellular identification.

24 Carbohydrates as an Energy Supply Plants store the sun s energy for future use by making glucose and converting it to starch. Animals break down glucose from food to produce energy. Stored as glycogen.

25 Lipids Lipids are another class of biomolecules which include fats, phospholipids. Lipids also provide energy! Glycerol backbone with fatty acid tails Made of C, H, O, and P in phospholipids.

26 Proteins Proteins are made up of amino acids. Proteins are twisted and folded into shapes that determine what the protein does. Elements Present: C,H,O,N Proteins are extremely important! DNA codes for proteins

27 Nucleic Acids A nucleic acid is a long chain of nucleotide units Elements present: C,H,O,N, P When we link NUCLEOTIDES together we form nucleic acids. DNA is made of Nucleic Acids

28 Biomolecule Review Name Monomer Elements Present Function Carbohydrate Monosaccharide C, H, O Quick energy source Lipid Glycerol backbone, fatty acid tails Examples Glucose Sucrose Starch Glycogen Chitin C, H, O, P Stored energy Phospholipid Fats Oils Proteins Amino Acid C, H, O, N Structure, enzymes, hormones Nucleic Acids Nucleotide C, H, O, N, P Genetic information Keratin Insulin Lactase DNA mrna trna

29 Water and Solutions Water has many unique properties Most of the unique properties of water result because water molecules form hydrogen bonds with each other. Hydrogen Bond: A partial charge within the water molecule causing attraction to other water molecules.

30 Ice Floats When water freezes, hydrogen bonds lock water molecules into a crystal structure that has empty space. This structure makes water less dense as a solid than as a liquid.

31 Water Absorbs and Retains Heat Hydrogen bonds are constantly breaking and reforming between molecules. Because of this water can absorb a large amount of heat without changing temperature. This property of water can also help organisms maintain a constant internal temperature. What vocabulary word does this remind you of?

32 Water Molecules Stick to Each Other Hydrogen bonds hold water molecules together. Cohesion - the attraction of particles of the same substance. This is why water can move up a plant. Water will stick to each other, so as one water molecule is pulled up, the other water molecules it is stuck to will also be pulled up. Those water molecules will pull up the water they are stuck to, and so on.

33 Water molecules stick to other polar substances Adhesion - attraction between particles of different substances. This also helps explain why water moves up a plant. As water moves up the tubes of the plant (called xylem), the water will stick to the walls, helping it not fall back down due to gravity.

34 Biological Reactions Living things carry out many chemical reactions that help maintain a stable internal environment. More energy is required to DRIVE these reaction than the body can provide. The body is just too cold. These reactions would not occur without ENZYMES!

35 Enzymes Enzymes ARE PROTEINS! An enzyme is a molecule that increases that rate of a biochemical reaction. By assisting in necessary biochemical reactions, enzymes help organisms maintain homeostasis. Without enzymes you would DIE!

36 Enzymes Continued Enzymes FIT with reactants (called substrates) like a lock fits a key. This is why shape is so important.

37 Enzymes Continued Each enzyme has an active site where the substrate binds. The shape of the site determines which substrates will bind to it. Each enzyme acts only on specific substrates. This is why SHAPE is so important. When substrates bind to the enzyme, it changes their structure and allows reactions to take place using less energy.

38 Enzymes and Substrates Enzyme-Substrate Complex Enzyme Enzyme Enzyme Products Active Site Substrate Products

39 Competitive Inhibitors

40 Competitive Inhibitor (orange)

41 Inhibitors with Allosteric Site

42 Acids and Bases Acids: compounds that form extra hydronium ions (H+) when dissolved in water. Your stomach uses a solution of hydrochloric acid, HCl, to digest food. Bases: compounds that form extra hydroxide ions (OH-) when dissolved in water. Example: Sodium Hydroxide (NaOH)

43 ph and buffers ph is a measure of how acidic or basic a solution is. ph of pure water is 7 Below 7 is acidic Above 7 is basic The ph of human blood must remain stable. Which vocabulary term does this remind you of? Buffers are substances that reacts to prevent ph changes in a solution.

44 Cosmetics often contain glycerol (C 3 H 8 O 3 ) which has three identical functional groups. Which type of bond holds these functional groups together? Ionic Covalent Hydrogen Sulfuric

45 Which of the following is used by the body as its main quick energy source? Lipid Carbohydrate Protein Nucleic Acid

46 Which ratio typically describes the Carbon:Hydrogen:Oxygen in a carbohydrate? 1:2:1 2:6:2 4:3:1 2:1:2

47 Elements present in lipids include: C,H,O C,H,O,N C,H,O,P C,H,O,N,P

48 Building blocks of carbohydrates are: Polysaccharides Disaccharides Monosaccharides Trisaccharides

49 Phospholipids are found in: Cell membranes Cell Wall Nucleus Ribosomes

50 Has names ending in the suffix -ose protein carbohydrates Nucleic acids lipids

51 Which line indicates a reaction where an enzyme is NOT present? A. Line A B. Line B

52 Which point on the line indicates the activation Energy? A. A B. B C. C D. D

53 Substrate attachment occurs at the site shape protein happy active

54 Enzymes are which type of biomolecule? Carbohydrate Protein Lipid Nucleic Acid

55 True or False: Enzymes increase the activation energy of a reaction. True False

56 True or False: Enzymes are important because they allow reaction to proceed at lower energies. True False

57 Enzymes are specific. enzyme substrate protein carbohydrate

58 What is the maximum number of covalent bonds that Carbon can make with hydrogen?