Chapter 1-15

The Big Ideas – E2 - I2

1. Evolution – the process of evolution drives the diversity and unity of life.

2. Energy – biological systems utilize free energy and molecular building blocks to grow, to reproduce, and to maintain dynamic homeostasis.

3. Information – living systems store, retrieve, transmit and respond to information essential to life processes.

4. Interactions – biological systems interact and these systems and their interactions possess complex properties.

Carbon

• Bonds covalently 4 times• Carbohydrates• Lipids• Proteins• Nucleic Acids• Isomers

ElementsMonomerID themUses/RolesExamplesStructure/function relationDehydration vs. hydrolysis

Functional Groups

• Hydroxyl• Amine• Carbonyl• Carboxyl• Sulfhydryl• Phosphate

Sulfhydryl

Cells

• Microscopes• Cell fractionation• Cell Size• Prokaryotic vs. Eukaryotic• Animal vs. Plant

Surface Area and Volume Math Question

• What is the SA/V for this cell? Round your answer to the nearest hundredths.

Answer

SA = 4πr2

= 4(3.14) 52

= 314Volume of a sphere= 4/3 π r3

= 4/3 (3.14)53

=523.33

SA/V=314/523.33 =.60

Endomembrane System

• Rough ER• Smooth ER• Golgi Apparatus• Nucleus• Nuclear envelope• Nucleolus

Organelles

• Ribosome• Lysosome• Peroxisome• Vacuole• Chloroplast• Mitochondria

Cytoskeleton

• Centrosomes• Centrioles• Cilia• Flagella• Basal body• Microtubules• Intermediate filaments• Microfilaments

Cell Surface

• Cell wall• Extracellular matrix• Intercellular junctions

– Plasmodesmata/gap junctions– Tight junctions– desmosomes

Gap Desmosomes Tight

During an investigation of a freshwater lake, an AP Biology student discovers a previously unknown microscopic organism. Further study shows that the unicellular organism is eukaryotic.

(a) Identify FOUR organelles that should be present in the eukaryotic organism and describe the function of each organelle.

(b) Prokaryotic cells lack membrane-bound organelles found in eukaryotes. However, prokaryotes must perform many of the same functions as eukaryotes. For THREE of the organelles identified in part (a), explain how prokaryotic cells carry out the associated functions. (c) According to the endosymbiotic theory, some organelles are believed to have evolved through a symbiotic relationship between eukaryotic and prokaryotic cells. Describe THREE observations that support the endosymbiotic theory.

Membrane structure and Function

• Fluid mosaic model– Phospholipids– Glycolipid– Glycoprotein– Intergral proteins– Peripheral proteins– Transport proteins

Diffusion• Definition• Factors that effect diffusion• Problems:

– The molar concentration of a sugar solution in an open beaker has been determined to be 0.3M. Calculate the solute potential at 27 oC. Round your answer to the nearest tenths.

Solute potential= –iCRT

i = The number of particles the molecule will make in water; for NaCl this would be 2; for sucrose or glucose, this number is 1 C = Molar concentration (from your experimental data) R = Pressure constant = 0.0831 liter bar/mole K T = Temperature in degrees Kelvin = 273 + °C of solution

Answer

• Solute potential= –iCRT-i= 1C= 0.3R = Pressure constant = 0.0831T= 27 +273=300K

Solute concentration= -7.5

Osmosis

• Definition• Hypotonic, Hypertonic, Isotonic• Water potential• Aquaporins• Osmoregulation• If ΨP = 0.3 MPa and ΨS = -0.45 MPa, the resulting Ψ is

– a. +0.75 MPa.– b. -0.75 MPa.– c. -0.15 MPa.– d. +0.15 MPa.

Other types of transport

• Facilitated diffusion• Active transport• Endocytosis• Exocytosis• Pinocytosis• Phagocytosis• Receptor mediated

endocytosis

Energy and the Cell

• Metabolism• 1st and 2nd law of thermodynamics• Kinetic vs. Potential energy• Endergonic vs. Exergonic• Energy coupling

– ATP– Phosphorylation

Enzymes• Activation energy• Active site• Induced fit• Things that effect the functioning of an enzyme

– Temperature– pH– Concentration– Competitive or noncompetitive

inhibition– Cofactors

• Allosteric regulation• Cooperativity

Cellular Respiration

• C6H12O6 + 6O2 ---> 6CO2 + 6H2O + ATP

• Redox reactions• Glycolysis• Krebs• Electron transport• Anaerobic respiration (fermentation)

Energy Harvest Phase

Order of electron carriers:FMN Fe-S Q Cyt b Fe-S Cyt c1 Cyt c Cyt a Cyt a3

Microbes produce acetone or methanol

An agricultural biologist was evaluating two newly developed varieties of wheat as potential crops. In an experiment, seedlings were germinated on moist paper towels at 20ºC for 48 hours. Oxygen consumption of the two-day-old seedlings was measured at different temperatures. The data are shown in the graph below.

(a) Calculate the rates of oxygen consumption in mL/min for each variety of wheat at 7°C and at 17°C. Show your work (including your setup and calculation).

(b) Explain the relationship between metabolism and oxygen consumption. Discuss the effect of temperature on metabolism for each variety of seedlings.

(c) In a second experiment, variety A seedlings at both temperatures were treated with a chemical that prevents NADH from being oxidized to NAD+. Predict the most likely effect of the chemical on metabolism and oxygen consumption of the treated seedlings. Explain your prediction.

The element carbon is contained in all organic compounds.

(a) Discuss the role of photosynthesis and cellular respiration in carbon cycling in the biosphere.

(b) For THREE of the following, predict and explain the effect on the carbon cycle if:

-- decomposers were absent -- deforestation occurred -- volcanic dust accumulated in the atmosphere -- the average ocean temperature increased

(c) Explain how increased CO2 in the atmosphere results in greater acidification of oceans and describe the effect on marine organisms. Include in your discussion TWO examples of how human activity can increase atmospheric CO2.

Photosynthesis

• 6 CO2 + 12 H2O + lt nrg C6H12O6 + 6 O2 + 6 H2O• Light reaction

– Cyclic electron vs. noncyclic electron flow

• Dark reaction– Carbon fixation– Reduction– Regeneration

C4• Uses a different enzyme to initially capture CO2

• Separates CO2 capture from carbon fixation• Still uses C3 Ps to make sugar, but only does so in the bundle sheath cells.

CAM• Open stomata at night to take in CO2.• The CO2 is stored as a C4 acid.• During the day, the acid is broken down and CO2 is fixed into sugar.• Still uses C3 Ps to make sugar.• Slow growth

C3/Photorespiration• When Rubisco accepts O2 instead of CO2 as the substrate.• Generates no ATP.• Decreases Ps output by as much as 50%.

Cell Communication

• Reception– Direct signaling– Local signaling– Long distance

• Transduction• Response

Reception

• Signal molecules• Receptor molecules• G-protein coupled• Tyrosine-kinase• Ion channels• Intracellular

Signal Transduction

• Amplification• Protein Kinase• Protein phosphatases• Secondary messengers

Responses

• Rearrange cytoskeleton• Transcription

Cell Cycle

• Cell Cycle– G1 , S , G2

• Checkpoints– G1 , G2 , M phase

• Mitosis– Prophase– Metaphase– Anaphase– Telophase/Cytokinesis

Meiosis

• Diploid Haploid• 2 divisions• Testicular/Ovarian cell to make sperm/egg• Independent assortment• Crossing over• Random fertilization• Mutations

Increases variety

1. The cell cycle is fundamental to the reproduction of eukaryotic cells.

(a) Describe the phases of the cell cycle.

(b) Explain the role of THREE of the following in mitosis or cytokinesis. Kinetochores Microtubules Motor proteins Actin filaments

(c) Describe how the cell cycle is regulated and discuss ONE consequence of abnormal regulation

Mendel Practice• Two heterozygotes produce 345 offspring

– What is your expected phenotypic ratio? 3:1 – How many individuals are expected to have the

dominant phenotype? 259 – How many individuals are expected to have the

recessive phenotype? 86 • In this genetic cross Aa x aa there are 714

offspring– How many individuals are expected to have the

dominant phenotype? 357 – How many individuals are expected to have the

recessive phenotype? 357

Mendel Practice• In a dihybrid cross between two heterozygotes, if

you have 360 offspring, what are your expected values? – Both dominant phenotypes 9/16 = .56 = 56% =

202

– One dominant; one recessive 3/16 = .19 = 19% = 68

– One recessive; one dominant 3/16 = .19 = 19% = 68

– Both recessive phenotypes 1/16 = .06 = 6% = 22

Exceptions to Mendel

• Incomplete dominance• Codominance• Sex-linked traits• Multiple alleles• Pleiotropy• Epistasis• Polygenic inheritance

Chapter 15 highlights

• Sex linked traits– examples– Seen more in males…why?

• X-inactivation• Gene mapping using recombination frequency• Chromosomal Mutations

– Nondisjunction, deletion, duplication, inversion, translocation

Questions Part 1 Review Booklet

• How do the unique chemical and physical properties of water make life on earth possible?– High specific Heat– Adhesion– Cohesion– Polarity

• What is the role of carbon in the diversity of life?

• How do cells synthesize and breakdown macromolecules?

• How do structures of biological molecules account for their function (carbs, proteins, lipids, and DNA)

• What are the similarities and differences between prokaryotic and eukaryotic cells?

• What are the evolutionary relationships between prokaryotic and eukaryotic cells?

• How does compartmentalization organize a cell’s functions?

• How are the structures of the various subcellular organelles related to their function?

• How do organelles function together in cellular processes?

• What is the current model of molecular architecture of membranes?

• How do variations in this structure account for functional differences among membranes?

• How does the structure of membranes provide for transport and recognition?

• What are various mechanisms by which substances can cross the membrane?

• In osmosis and diffusion lab, how was osmosis measure in both living (cells/potatoes) and artificial (dialysis tubing)?

• What was the independent variable in the dialysis bag part of the lab?– Dependent variable?– Control?– Controlled variables?

• What was the independent variable in the potato part of the lab?– Dependent variable?– Control?– Controlled variables?

Concept MapAtom, compound, carbohydrate, lipid, protein, nucleic acid, organelles, nucleus, mitochondria, cell membrane, golgi apparatus, ER, prokaryotic cell, eukaryotic cell

Questions Part 2 Review Booklet

• How do the laws of thermodynamics relate to the biochemical processes that provide energy to living systems?

• How do enzymes regulate the rate of chemical reactions?

• How does the specificity of an enzyme depend of its structure?

• How is the activity of an enzyme regulated?

• How does the cell cycle assure genetic continuity?

• How does mitosis allow for the even distribution of genetic information to new cells?

• What are the mechanisms of cytokinesis?• How is the cell cycle regulated?

• How can aberrations in the cell cycle lead to tumor formation?

• Why is meiosis important in heredity?• How is meiosis related to gametogenesis?• What are the similarities and differences

between gametogenesis and animals and plants?

• What is the role of ATP in coupling the cell’s anabolic and catabolic processes?

• How does chemiosmosis function in bioenergetics?

• How are organic molecules broken down by catabolic pathways?

• What is the role of oxygen in energy-yielding pathways?

• How do cells generate ATP in the absence of oxygen?

• How does photosynthesis convert light energy into chemical energy?

• How are the chemical products of the light-trapping reactions coupled to the synthesis of carbohydrates?

• What kinds of photosynthetic adaptations have evolved in response to different environmental conditions?

• What interactions exist between photosynthesis and cellular respiration?

• How was photosynthetic rate measured in the photosynthesis lab?

• What was the independent variable in the photosynthesis lab?– Dependent variable?– Control?– Controlled variables?

• How was respiration rate measured in the respiration lab (pea lab)?

• What was the independent variable in the lab?– Dependent variable?– Control?– Controlled variables?

Concept mapCell cycle, interphase, growth, DNA replication, mitosis, meiosis, homologous chromosomes, separations of chromosomes, cancer, checkpoints, regulatory proteins.

Concept MapUnicellular, multicellular, local regulators, long distance regulation, contact, receptor, signal transduction, enzyme cascade, response