chapter nine: Cellular Respiration-Harvesting Chemical Energy

Main questions:

1. The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the?

H+ concentration across the membrane holding ATP synthase.

2. In mitochondria, exergonic redox reactions?

Provide the energy that establishes the proton gradient

3. The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is?

NAD+

Main Facts:

1. To keep working, a cell must regenerate the ATP it uses.

2. The breakdown of glucose and other organic fuels is exergonic. Starting with glucose or another organic molecule and using O2, aerobic respiration yields water, CO2, and energy in the form of ATP and heat.

3. Glycolysis and the citric acid cycle supply electrons to the electron transport chain, which drives oxidative phosphorylation.

4. About 40% of the energy stored in a glucose molecule is transferred to ATP during cellular respiration, producing a maximum of about 38 ATP.

5. Glycolysis occurs in nearly all organisms and probably evolved in ancient prokaryotes before there was O2 in the atmosphere.

Summary:

Key terms:
1. Fermentation: is a partial degradation of sugars that occurs without the use of oxygen.

2. Aerobic respiration: oxygen is consumed as a reactant along with the organic fuel.

3. Cellular respiration: includes both aerobic and anaerobic processes.

4. Oxidative phosphorylation: it is powered by the redox reactions of the electron transport chain.

5. Substrate-level phosphorylation: a smaller amount of ATP is formed directly in a few reactions of glycolysis and the citric acid cycle by a mechanism.

6. ATP synthase: the enzyme that actually makes ATP and ADP and inorganic phosphate.

7. Chemiosmosis: Is used to drive cellular work such as the synthesis of ATP.

8. Obligate anaerobes: carry out only fermentation or anaerobic respiration and in face cannot survive in the presence of oxygen.

9. Oxidizing agent-The electron acceptor in a redox reaction.

10. Cytochrome-An iron-containing protein that is a component of electron transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membranes of prokaryotic cells.

Video: http://www.youtube.com/watch?v=xbJ0nbzt5Kw

Chapter ten: Photosyntheisis

Main questions:

1. The light reactions of photosynthesis supply the Calvin cycle with?

ATP and NADPH.

2. How is photosynthesis similar in C4 plants and CAM plants?

In both cases, rubisco is not used to fix carbon initially.

3. In mechanism, photophosphorylation is most similar to?

The Calvin cycle.

Main Facts:

1.Chloroplasts split water into hydrogen and oxygen, incorporating the electrons of hydrogen into sugar molecules.

2. The light reactions in the thylakoid membranes split water, releasing O2, producing ATP, and forming NADPH.

3. The Calvin cycle in the stroma forms sugar from CO2, using ATP for energy and NADPH for reducing power.

4. Light is a form of electromagnetic energy. The colors we see as visible light include those wavelengths that drive photosynthesis.

5. A pigment absorbs visible light of specific wavelengths.

Summary:

Key terms:
1. Chlorophyll: the green pigment located within chloroplasts.

2. Mesophyll: The tissue in the interior of the leaf.

3. Thylakoids: An elaborate system of interconnected membranous sacs.

4. Spectrophotometer: The ability of a pigment to absorb various wavelengths of light can be measured with an instrument.

5. Absorption spectrum: a pigment’s light absorption versus wavelength.

6. Carotenoids: hydrocarbons that are various shades of yellow and orange because they absorb violet and blue-green light.

7. Linear electron flow: it occurs during the light reactions of photosynthesis.

8. Glyceraldehyde-3-phosphate: a three-carbon sugar.

9. C3 plants: the first organic product of carbon fixation is a three-carbon compound.

10. cyclic electron flow-A route of electron flow during the light reactions of photosynthesis that involves only photosystem I and that produces ATP but not NADPH or O2.

Video: http://www.youtube.com/watch?v=hj_WKgnL6MI

Chapter eleven: cell communication

Main questions:

1. Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because?

They amplify the original signal manifold.

2. The activation of receptor tyrosine kinases is characterized by?

Dimerization and phosphorylation

3. Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because?

Intracellular receptors are present only in target cells.

Main Facts:

1. In local signaling, animal cells may communicate by direct contact or by secreting local regulators, such as growth factors or neurotransmitters.

2. Intracellular receptors are cytoplasmic or nuclear proteins.

3. At each step in a pathway, the signal is transduced into a different form, commonly a shape change in a protein.

4. Some pathways regulate genes by activating transcription factors, proteins that turn specific genes on or off.

5.Each catalytic protein in a signaling pathway amplifies the signal by activating multiple copies of the next component of the pathway.

Summary:

Key terms:
1. Signal transduction pathway: a signal on a cell’s surface is converted to a specific cellular response is a series of steps.

2. Local regulators: influence cells in the vicinity.

3. Reception: is the target cell’s detection of a signaling molecule coming from outside the cell.

4. Transduction: the binding of the signaling molecule changes the receptor protein in some way, initiating the process of transduction.

5. Response: In the third stage of cell signaling, the transduced signal finally triggers a specific cellular response.

6. Ligand: The term for a molecule that specifically binds to another molecule, of ten a larger one.

7. Ligand-gated ion channel: is a type of membrane receptor containing a region that can act as a “gate” when the receptor changes shape.

8. Protein kinase: the general name for an enzyme that transfers phosphate groups from ATP to a protein is protein kinase.

9. Protein phosphatases: enzymes that can rapidly remove phosphate groups from proteins, a process called dephosphorylation.

10. cAMP: a compound called cyclic adenosine monophosphate, abbreviated cyclic AMP.

Video: http://www.youtube.com/watch?v=U6uHotlXvPo

Chapter twelve: The cell cycle

Main questions:

1. What is chromosome made of?

Made of a DNA and protein complex called Chromatin.

2. The steps of Mitotic division of an animal cell?

G2 of Interphase, Prophase, Prometaphase, Metaphase, Anaphase, Telophase and Cytokinesis.

3. What is cancer cells?

Do not stop dividing. The control mechanisms for cell division have failed.

Main Facts:

1. Cells duplicate their genetice materical before they divide, ensuring that each daughter cell receives an exact copy of the genetic material, DNA.

2. DNA is partitioned among chromosomes.

3. Since prokaryotes preceded eukaryotes by more than a billion years, it is likely that mitosis evolved from prokaryotic cell division.

4. Molecules present in the cytoplasm regulate progress through the cell cycle.

5. Cancer cells elude normal regulation and divide out of control, forming tumors.

Summary:

Key terms

1. Cell division: The reproduction of cells.

2. Genome: The genetic material of an organism or virus; the complete complement of an organism’s or virus’s genes along with its noncoding nucleic acid sequences.

3. Sister chromatids: Either of two copies of a duplicated chromosome attached to each other by proteins at the centromere and , some tiems, along the arms.

4. Centromere: The specialized region of the chromosome where two sister chromatids are most closely attached.

5. Mitosis: a process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase.

6. Cytokinesis: The division of the cytoplasm to form two separate daughter cells immediately after mitosis daughter cells immediately after mitosis, meiosis I, or meiosis II.

7. Meiosis: a modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication.

8. Kinetochore: A structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle.

9. Binary fission: A method of asexual reproduction by “division in half.” In prokaryotes, binary fission does not involve mitosis; but in single-celled eukaryotes that undergo binary fission, mitosis is part of the process.

10.Growth factor: a protein that must be present in the extracellular environment for the growth and normal development of certain types of cells.

Video: http://www.youtube.com/watch?v=aSpRpf1Ny9A