Dispatch • Write 10 facts about enzymes • We’ve had 6 exit quizzes, how many have you mastered? • A student asked Ms. Morris, “Ms. Morris would you get mad if I came in every Tuesday and retook the quizzes.” What do you think Ms. Morris replied Pick up 2 papers and your 2 FRQs and Hardy Lab Report
Objectives I can explain how the structure of a protein affects its function I can explain how substrate concentration affects the rate of an enzyme I can identify and describe characteristics of prokaryotic cells and eukaryotic cells
Why does a change in an amino acid change the quartnery structure of the protein? Give a real life example. Use at least 5 terms. Underline
Proteins (Sickle-cell Disease) • Results from a single amino acid substitution in the protein hemoglobin
Normal hemoglobin Sickle-cell hemoglobin Primary structure Primary structure . . . . . . Exposed hydrophobic region Glul Val Val His Leu Thr Pro Glu Val His Leu Pro Glu Thr 5 6 7 3 4 5 6 7 1 2 1 2 3 4 Secondaryand tertiarystructures Secondaryand tertiarystructures subunit subunit Quaternary structure Hemoglobin A Quaternary structure Hemoglobin S Molecules interact with one another tocrystallize into a fiber, capacity to carry oxygen is greatly reduced. Function Molecules donot associatewith oneanother, eachcarries oxygen. Function 10 m 10 m Normal cells arefull of individualhemoglobinmolecules, eachcarrying oxygen Red bloodcell shape Red bloodcell shape Figure 5.21 Hemoglobin structure and sickle-cell disease Fibers of abnormalhemoglobin deform cell into sickle shape.
Proteins (Denaturing) • Conditions that affect secondary and tertiary structure: • High temperature • pH changes • High concentrations of polar molecules • Denaturation: loss of 3-dimensional structure and thus function of the protein
Correctlyfoldedprotein Polypeptide Cap Hollowcylinder The cap attaches, causing the cylinder to change shape insuch a way that it creates a hydrophilic environment for the folding of the polypeptide. The cap comesoff, and the properlyfolded protein is released. Chaperonin(fully assembled) Steps of ChaperoninAction: An unfolded poly- peptide enters the cylinder from one end. 2 1 3 Figure 5.23 Proteins (folding) • Proteins can sometimes fold incorrectly and bind to the wrong ligands. • Chaperonins are proteins that help prevent this.
In Chapter 5, they mention sickle cell disease. How does this disease affect the primary, secondary, tertiary structures of the protein?
ACTIVITY: Take 2 pieces of different colored clay • With 1 piece of clay, make the enzyme and its active site • With the other piece of clay, make the substrates • When told, we will make products
Denaturing • http://lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html
How do enzymes speed up reactions? • http://www.dynamicscience.com.au/tester/solutions/biology/enz1asml.gif
Entrance Quiz Chapters 6 + 7 • What role do ribosomes play in carrying out genetic instructions? • Discuss 2 common characteristics of the mitochondria and chloroplast. • Draw a cell membrane and label 2 components • Two molecules, CO2 and H2O can cross the lipid bilayer without help from membrane bound proteins, what allows them to do this? • Compare passive and active transport
Entrance Quiz Chapters 6 + 7 • What role do ribosomes play in carrying out genetic instructions? RIBOSOMES GET INSTRUCTIONS FROM RNA TO SYNTHESIZE PROTEINS 2) Discuss 2 common characteristics of the mitochondria and chloroplast. BOTH HAVE A DOUBLE MEMBRANE, RIBOSOMES, AND THEIR OWN DNA 3) Draw a cell membrane and label 2 components 4) Two molecules, CO2 and H2O can cross the lipid bilayer without help from membrane bound proteins, what allows them to do this? THEY ARE SMALL MOLECULES + DIFFUSION?PASSIVE TRANSPORT 5) Compare passive and active transport PASSIVE REQUIRES NO ENERGY, GOES FROM HIGH TO LOW ACTIVE TRANSPORT REQUIRES ATP ENERGY AND GOES FROM LOW TO HIGH
I can identify and describe characteristics of prokaryotic cells and eukaryotic cells
Cytology: science/study of cells • Light microscopy resolving power~ measure of clarity X400 • Electron microscopy TEM ~ electron beam to study cell ultrastructure SEM ~ electron beam to study cell surfaces • Cell fractionation ~ cell separation; organelle study • Ultracentrifuge ~ cell fractionation; 130,000rpm
A cell is a living unit greater than the sum of its parts • While the cell has many structures that have specific functions, they must work together. • STRUCTURE=FUNCTION
Prokaryotebacteria cells Types of cells - no organelles - organelles Eukaryoteanimal cells Eukaryoteplant cells
Cell Types: Prokaryotic • Nucleoid: DNA concentration • No organelles with membranes Flagella—9 + 2 microtubules • Cell wall made of cellulose (polysaccharide) • Ribosomes:protein synthesis • Plasma membrane: (all cells); semi-permeable • Cytoplasm/cytosol(all cells)
Cell types: Eukaryotic • Nucleus:membrane enclosedorganelle containing chromosomes • Membrane bound organellesof specialized form and function • Generally larger than prokaryotic cells
Cell Size • As cell size increases, the surface area to volume ratio decreases • Rates of chemical exchange may then be inadequate for cell size if TOO BIG • Cell size, therefore, remains small
Exit Quiz • List 10 facts about enzymes 2) Draw and label a prokaryote cell