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Metabolism: Energy and Enzymes

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Presentation on theme: "Metabolism: Energy and Enzymes"— Presentation transcript:

1 Metabolism: Energy and Enzymes
Chapter 6

2 LAB Tues 9/16 *next week! Be there!

3 Biological Science building room 136 -13 on map extra 5 min to get there

4 Quiz Next Time macromolecules

5 Energy = the ability to do work
Kinetic Energy (energy of motion) Potential Energy (stored energy) First Law of Thermodynamics - the law of conservation of energy (not created or destroyed) Second Law of Thermodynamics - energy cannot be changed without a loss of usable energy (heat)

6 QOD Staple/tape is the graphic organizer as last QOD Today:
What are the 4 shapes of proteins? Draw a small sketch to go with your explanation or each shape

7 a. carbohydrate b. lipids c. protein d. nucleic acids
MATCHING a.  carbohydrate     b.  lipids c.  protein               d.  nucleic acids 1.  contains adenine and thymine 2.  lactose 3.  chains of amino acids 4.  long term energy storage 5.  cholesterol 6.  chains of fatty acids and glycerol 7.  plant cell walls 7. Cellulose = carbohydrate

8 Chemical Reaction Reactants Products
Reactants: starting substances, on the left side of the arrow. Products: substances formed during the reaction, on the right side of the arrow. Baking soda + vinegar water + CO2 Reactants Products

9 What are the reactants and products?
6CO2 + 6H2O C6H12O6 Reactants Products H2O2 H2O + O2 Reactants Products

10 Reactants --> Products
Metabolic Reactions Reactants --> Products  Exothermic - releases energy  Endothermic = absorbs energy

11 This reaction is exothermic and released heat energy.
Chapter 6 Chemistry in Biology This reaction is exothermic and released heat energy. The energy of the product is lower than the energy of the reactants.

12 This reaction is endothermic and absorbed heat energy.
Chapter 6 Chemistry in Biology 6.2 Chemical Reactions This reaction is endothermic and absorbed heat energy. The energy of the products is higher than the energy of the reactants.

13 Metabolic Pathways & Enzymes (6-3)
Enzyme - protein molecule that functions as an organic catalyst to speed reactions Substrate - reactants in the enzymatic reaction, this is what an enzyme attaches to Activation Energy- the energy required to cause the reaction

14 activation energy: the minimum amount of energy needed for a reaction.
Chemistry in Biology Energy of Reactions activation energy: the minimum amount of energy needed for a reaction. Enzymes lower the activation energy

15 Properties of Enzymes:
Enzymes are made of proteins. They speed up chemical reactions inside the cytoplasm. They are needed only in small amounts They remain unchanged after each reaction and can therefore be reused Each enzyme is specific for a substrate

16 Substrates: reactants that bind to the enzyme
Chapter 6 Chemistry in Biology Substrates: reactants that bind to the enzyme active site: specific location where a substrate binds on an enzyme

17 Lock and Key Model Each enzyme acts on a specific substrate

18 Induced Fit Model - substrates and enzymes fit together
Induced Fit Model - substrates and enzymes fit together like a lock and key.  Degradation vs Synthesis                  breaking down vs building

19 Factors Affecting Enzymatic Speed
1. Substrate concentration 2. Temperature & pH * 3. Enzyme concentration Enzymes can be denatured - they change shape so much that they are no longer effective. High temp or pH can cause denaturation. 

20 Siamese cats have an enzyme that works at lower temperatures only, causing the nose and ears to become a darker color than the rest of the body.

21 Competitive Inhibition vs. Noncompetitive Inhibition (allosteric site)
Enzymatic Inhibition - when a substance binds to an enzyme and decreases its activity. (Usually reversible) Competitive Inhibition  vs. Noncompetitive Inhibition (allosteric site) **Both are forms of feedback inhibition Normal Inhibited: competitive Non- competitive

22

23 Some inhibitors are NOT reversible - poisons like cyanide, lead poisoning all affect enzymes
QUESTION: What type of inhibition is pictured below?

24 Enzyme Animation (Tutorial) 
Enzyme Quiz

25 Enzyme Lab 2H2O2 ----> 2H2O + O2
Hydrogen Peroxide is broken down by the enzyme catalase within cells.    Potatoes hold the enzyme catalase, which will speed up the breakdown of hydrogen peroxide

26 Proteins have four shapes
1. Primary Structure - sequence of amino acids that form the polypeptide chain 2. Secondary Structure - Parts of the polypeptide fold into local patterns (alpha helix or pleated sheet) 3. Tertiary Structure - the overall 3D shape (globular or fibrous) 4. Quaternary Structure - consists of two or more polypeptide chains or subunits

27 Factors Affecting Enzymatic Speed
1. Substrate concentration 2. Temperature & pH * 3. Enzyme concentration Enzymes can be denatured - they change shape so much that they are no longer effective. High temp or pH can cause denaturation. 

28 The activity of catalase can be seen by the bubbling of oxygen during the reaction
Generally speaking, catalase reactions occur faster at warmer temperatures. If temperature is too hot (boiling) then the enzyme becomes denatured

29 Competitive Inhibition Noncompetitive Inhibition (allosteric site)
Enzymatic Inhibition - when a substance binds to an enzyme and decreases its activity. (Usually reversible) Competitive Inhibition  Noncompetitive Inhibition (allosteric site) **Both are forms of feedback inhibition Normal Inhibited: competitive Non- competitive

30 Both cofactors and coenzymes help to complete the structure of a conjugated enzyme
CO-ENZYME is a small organic non-protein MOLECULE that carries chemical groups between enzymes while a ex: iron, magnesium or zinc. CO-FACTOR is a non-protein CHEMICAL COMPOUND that is bound tightly to an enzyme and is required for catalysis. ex: NAD+, NADP+ and FAD+

31 Virtual Labs with Enzymes
McGraw Hill Lab Bio 114  Enzymes Lab Bench Enzyme Catalysis

32 ATP Ribose (sugar) release energy Add energy ADP Diphosphate Energy stored in ATP is released by breaking the bond between the 2nd and 3rd phosphates.

33 ATP Energy stored in ATP is released by breaking the bond between the 2nd and 3rd phosphates. 2 Phosphate groups P ADP Copyright Pearson Prentice Hall

34 ATP - the energy currency of cells (adenosine triphosphate)
Functions: 1. CHEMICAL WORK - Supplies energy needed to make macromolecules that make up the cell (and organism) 2. TRANSPORT WORK - Supplies energy needed to pump substances across the cell membrane 3. MECHANICAL WORK - supplies energy needed to make muscles contract and other cellular parts to move (flagella)

35 How do cells make ATP? Cellular respiration Photosynthesis
Electron transport chain Chemiosmosis= production of ATP due to hydrogen ion gradient across a membrane

36

37 ATP

38 Review videos https://www.youtube.com/watch?v=ok9esggzN18 https://www.youtube.com/watch?v=5GMLIMIVUvo


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