1 / 19

Monday 10-21-13 Objective

Monday 10-21-13 Objective . SWBAT: Discuss why enzymes, nucleic acids and ATP are important to the body. Resulting in: A better understanding of the human body. As measured by: An Exit Slip with 80% mastery. Enzymes. Biological catalysts

onella
Download Presentation

Monday 10-21-13 Objective

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Monday 10-21-13 Objective • SWBAT: Discuss why enzymes, nucleic acids and ATP are important to the body. • Resulting in: A better understanding of the human body. • As measured by: An Exit Slip with 80% mastery.

  2. Enzymes • Biological catalysts • Lower the activation energy, increase the speed of a reaction (millions of reactions per minute!)

  3. WITHOUT ENZYME WITH ENZYME Activation energy required Less activation energy required Reactants Reactants Product Product Figure 2.20

  4. Characteristics of Enzymes • Often named for the reaction they catalyze; usually end in -ase (e.g., hydrolases, oxidases) • Some functional enzymes (holoenzymes) consist of: • Apoenzyme (protein) • Cofactor (metal ion) or coenzyme (a vitamin)

  5. Product (P)e.g., dipeptide Substrates (S)e.g., amino acids Energy isabsorbed;bond isformed. Water isreleased. Peptidebond + H2O Active site Enzyme-substratecomplex (E-S) Enzyme (E) Enzyme (E) 1 2 Substrates bindat active site.Enzyme changesshape to holdsubstrates inproper position. Internalrearrangementsleading tocatalysis occur. 3 Product isreleased. Enzymereturns to originalshape and isavailable to catalyzeanother reaction. Figure 2.21

  6. Substrates (S)e.g., amino acids + Active site Enzyme-substratecomplex (E-S) Enzyme (E) 1 Substrates bindat active site.Enzyme changesshape to holdsubstrates inproper position. Figure 2.21, step 1

  7. Substrates (S)e.g., amino acids Energy isabsorbed;bond isformed. Water isreleased. + H2O Active site Enzyme-substratecomplex (E-S) Enzyme (E) 1 2 Substrates bindat active site.Enzyme changesshape to holdsubstrates inproper position. Internalrearrangementsleading tocatalysis occur. Figure 2.21, step 2

  8. Product (P)e.g., dipeptide Substrates (S)e.g., amino acids Energy isabsorbed;bond isformed. Water isreleased. Peptidebond + H2O Active site Enzyme-substratecomplex (E-S) Enzyme (E) Enzyme (E) 1 2 Substrates bindat active site.Enzyme changesshape to holdsubstrates inproper position. Internalrearrangementsleading tocatalysis occur. 3 Product isreleased. Enzymereturns to originalshape and isavailable to catalyzeanother reaction. Figure 2.21, step 3

  9. Nucleic Acids • DNA and RNA • Largest molecules in the body • Contain C, O, H, N, and P • Building block = nucleotide, composed of N-containing base, a pentose sugar, and a phosphate group

  10. Deoxyribonucleic Acid (DNA) • Four bases: • adenine (A), guanine (G), cytosine (C), and thymine (T) • Double-stranded helical molecule in the cell nucleus • Provides instructions for protein synthesis • Replicates before cell division, ensuring genetic continuity

  11. Sugar: Deoxyribose Base: Adenine (A) Phosphate Phosphate Thymine (T) Sugar Adenine nucleotide Thymine nucleotide Hydrogen bond (a) Deoxyribose sugar Sugar-phosphate backbone Phosphate Adenine (A) Thymine (T) Cytosine (C) Guanine (G) (b) (c) Computer-generated image of a DNA molecule Figure 2.22

  12. Ribonucleic Acid (RNA) • Four bases: • adenine (A), guanine (G), cytosine (C), and uracil (U) • Single-stranded molecule mostly active outside the nucleus • Three varieties of RNA carry out the DNA orders for protein synthesis • messenger RNA, transfer RNA, and ribosomal RNA

  13. Adenosine Triphosphate (ATP) • Adenine-containing RNA nucleotide with two additional phosphate groups

  14. High-energy phosphate bonds can be hydrolyzed to release energy. Adenine Phosphate groups Ribose Adenosine Adenosine monophosphate (AMP) Adenosine diphosphate (ADP) Adenosine triphosphate (ATP) Figure 2.23

  15. Function of ATP • Phosphorylation: • The addition of a phosphate (PO43-) group to a protein or other organic molecule, helps energize other molecules • Such “primed” molecules perform cellular work (life processes) using the phosphate bond energy • Phosphorylation turns many protein enzymes on and off, thereby altering their function and activity

  16. Solute + Membrane protein (a) Transport work: ATP phosphorylates transport proteins, activating them to transport solutes (ions, for example) across cell membranes. + Relaxed smooth muscle cell Contracted smooth muscle cell Mechanical work: ATP phosphorylates contractile proteins in muscle cells so the cells can shorten. (b) + Chemical work: ATP phosphorylates key reactants, providing energy to drive energy-absorbing chemical reactions. (c) Figure 2.24

  17. Check your understanding: • 1. How do enzymes reduce the amount of activation energy needed to make a chemical reaction go? • 2. How do DNA and RNA differ in the bases and sugars they contain? • 3. What are two important roles of DNA? • 4. Glucose is an energy rich molecule. So why do body cells need ATP? • 5. What change occurs in ATP when it releases energy?

  18. Simple and Stratified Epithelia • Read and Highlight key terms. You will be required to match images to terms or terms to definitions on a quiz. • Use key terms to label diagrams. • Color diagrams as follows: • Purple = nuclei • Blue = cytoplasm • Red = basement membrane

  19. Answers to Check your understanding: • Enzymes hold the substrate(s) in a desirable position to interact. • DNA contains deoxyribose sugar and the bases A, T, G, and C. RNA contains ribose sugar and the bases A, U, G, and C. • DNA dictates protein structure by its base sequence and reproduces itself before a cell divides to ensure that the genetic information in the daughter cells is identical.

More Related