Chapter 13: Meiosis and Sexual Life Cycles

3 Main Questions:

- What is heredity?

The transmission of traits from one generation the the next.

- What is genetics?

Genetics is the scientific study of heredity and heredity variation.

- What are the two types of reproduction?

Asexual reproduction and sexual reproduction.

5 Main Facts:

- One of the characteristics of life is the ability of organisms to reproduce their own kind.

- Offspring resemble their parents more than they do unrelated individuals.

- Parents endow their offspring with coded information in the form of hereditary units called gene.

- Only organisms that reproduce asexually produce offspring that are exact copies of themselves.

- In meiosis, DNA replication occurs during interphase before meiosis I begins.

Diagram

A spindle apparatus was formed. In the late prophase II, chromososmes, each still composed of two chromatids associated at the centromere, move toward the metaphase II plate.

Summary

One of the characteristics of life is the ability of organisms to reproduce their own kind. The transmission of traits from one generation to the next is called inheritance. However, sons and daughters are not identical copies of their parent or their siblings.

Parents endow their offspring with coded information in the form of hereditary units called genes. The transmission of hereditary traits has its molecular basis in the precise replication of DNA, which produces copies of genes that can be passed along from parents to offspring.

Video

http://www.youtube.com/watch?v=D1_-mQS_FZ0

10 Key Terms

- Variation: differences between members of the same species.

- Locus: a specific place along the length of a chromosome where a given gene is located.

- Gamete: a haploid reproductive cell, such as an egg or sperm.

- Asexual reproduction: the generation of offspring from a single parent that occurs without the fusion of gametes.

- Sexual reproduction: a type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from the gametes of the parents.

- Karyotype: a display of the chromosome pairs of a cell arranged by size and shape.

- Sex chromosome: a chromosome responsible for determining the sex of an individual.

- Autosome: a chromosome that is not directly involved in determining sex.

- Fertilization: the union of haploid gametes to produce a diploid zygote.

- Zygote: the diploid product of the union of haploid gametes during fertilization.

Chapter 12: The Cell Cycle

3 Main Questions

- What is cell division?

The reproduction of cells.

- How many stage are there in the Mitotic division of an animal cell?

There are 5 stages in Mitosis.

- What is genome?

The genetic information of a cell.

5 Main Facts:

- The continuity of cell is based on the reproduction o

f cells.

- The reproduction of an ensemble as complex as a cell can not occur by a mere pinching in half; a cell is not like a soap bubble that simply enlarges and splits into two.

- The cell division process is an integral part of the cell cycle, the life of a cell from the time it is first formed from a dividing parent cell until its own division into two cells.

- A particular human cell might undergo one division in 24 hours.

- Mitosis is conventionally broken down into five stages: prophase, prometaphase, metaphase, anaphase, and telophase.

Diagram

This is the interphase stage of mitotic division. A nuclear envelop bounds the nucleus which contains one or more nucleoli. Two centrosomes formed by replication of a single centrosome. In an animal cells, each centrosome features two centrioles. Chromosomes duplicated during S phase and can not be seen individually because they have not yet condensed.

Summary

The ability of organisms to reproduce their own kind is the one characteristic that best distinguishes living things from nonliving matter. This unique capacity to procreate, like all biological functions, has a cellular basis. Every cell from a cell. The continuity of life is based on the reproduction of cells, or cell division.

The replication and distribution of so much DNA is manageable because the DNA molecules are packaged into chromosomes, so named because they take up certain dyes used in microscopy.

Video:

http://www.youtube.com/watch?v=lf9rcqifx34

10 Key Terms:

- Somatic cell: any cell in a multi cellular organism except a sperm or egg.

- Gamates: a haploid reproductive cell, such as an egg or sperm.

- Sister chromatid : either of two copies of a duplicated chromosome attached to each other by proteins at the centromere and , sometimes, along the arms.

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

- Centrosome: structure present in the cytoplasm of animal cells, important during cell division; functions as a microtubule.

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

- Interphase: the period in the cell cycle when the cell is not dividing.

- Metaphase: The third of mitosis, in which the spindle is complete and the chromosomes, attached to microtubules at their kinetochores, are all aligned at the metaphase plate.

- Anaphase: the fourth stage mitosis, in which the chromatids of each chromosome have separated and the daughter chromosomes are moving to the poles of the cell.

- Prophase: the first stage of mitosis, in which the chromatin condenses, the mitotic spindle begins to form, and the nucleolus disappears, but the nucleus remains intact.

Chapter 11: Cell Communication

3 Main Questions:

- How are cells of yeast identify their mates?

Cells of yeast identify their mates by chemical signaling.

- What is signal transduction pathway?

The process of which a signal on a cell's surface is converted to a specific cellular response.

- What are the two mating types?

Mating type a and mating type α.

5 Main Facts:

- Numerous cells can simultaneously receive and respond to the molecules of growth factor produced by a single cell in their vicinity.

- Both animals and plants use chemicals called hormones for long distance signaling.

- Epinephrine stimulates glycogen phosphorylase.

- There are three stages of cell signaling: reception, transduction, response.

- Ligand binding is similar to the binding of an allosteric regulator to an

enzyme, causing a shape change that either promotes or inhibits enzyme activity.

Diagram

The receptor protein is activated, it is detected by specific relay proteins inside the cell. Each protein binds to a specific phosphorylated tyrosine, undergoing a resulting structural change that activates the bound protein. Each activated protein triggers a transduction pathway, leading to cellular response.

Summary

Cell to cell communication is essential for multicellular organism. Trillions of cells in a multicellular organisms must communicate with each other to coordinate their activities in a way that enables the organism to develop from a fertilized egg, then survive and reproduce in turn.

There are three stages of cell signaling: reception, transduction, response. Reception is the detection of target cell of a signaling molecule coming from outside of the cell. Transduction is the binding of the signaling molecule changes the receptor protein in some way, initiating the process of transduction.

Video:

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

10 Key Terms:

- Local regulator: a secreted molecule that influences cells near where it is secreted.

- Hormones: in multicellular organisms, one of many types of secreted chemicals that are formed in specialized cells, travel in body fluids , and act on specific target cells in other parts of the body to change their functioning.

- Ligand: a molecule that binds specifically to another molecule, usually a larger one.

- G protein: a GTP-binding protein that relays signals from a plasma membrane signal receptor to other signal transduction proteins inside the cell.

- G protein coupled receptor: a signal receptor protein in the plasma membrane that responses to the binding of a signaling molecule by activating a G protein.

- Receptor tyrosine kinase: a receptor protein in the plasma membrane, the cytoplasmic part of which can catalyze the transfer of a phosphate group from ATP to a tyrosine on another protein.

- Ligand-gated ion channel: a protein pore in cellular membranes that opens or closes in respones to a signaling chemical, allowing or blocking the flow of specific ions.

- Protein kinase: an enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein.

- Protein phosphatase: an enzyme that removes phosphate groups from proteins, often functioning to reverse the effect of a protein kinase.

- Second messenger: a small, nonprotein, water soluble or ion, such as a calcium ion or cyclic AMP, that relays a signal to a cell's interior in response to a signaling molecule bound by a signal receptor protein.

Chapter 10: Photosynthesis

3 Main Questions:

- What is the formula for photosynthesis?

6Co2 + 6H2O + Light Energy --> C6H12O6 +6O2

- What is photosynthesis?

The conversion of light energy to chemical energy that is stored in sugars or other organic compounds.

-Where does photosynthesis take place?

Plants, animals and certain prokaryotes.

5 Main Facts:

- Plants are photoautotrophs, organism that use lights as a source of energy to synthesize organic substances.

- Decomposers are some heterotrophs consume the remains ofdea organisms by decomposing and feeding on organic litter such as carcasses, feces, and fallen leaves.

- The two stages of photosynthesis are light reaction and Calvin cycle.

- The light reactions use solar power to reduce NADP+ to NADPH by adding a pair of electrons along with an H+.

- The chloroplast uses light energy to make sugar by coordinating the two stages of photosynthesis.

Diagram

The diagram briefly showed the whole process of photosynthesis. To be specific, it shows the main reactants and products of the light reaction and the Calvin cycle as they occurs in a plant cells. Enzymes in the chloroplast and cytosol convert G3P, the product of Calvin cycle, to many other organic compounds.

Summary

Life on Earth is solar powered. The chloroplasts of plants capture light energy from the sun and covert it to chemical energy stored in sugar and other organic molecules. This process is called photosynthesis. Photosynthesis consists of two main stages which are light reaction and Calvin cycle.

The light reaction is a step that convert solar energy into chemical energy. Calvin cycle starts by separating CO2 from the air into organic molecules already present in the chloroplast. In addition, this first step of Calvin cycle into organic compounds is called carbon fixation. Then the Calvin cycle reduces the fixed carbon to carbohydrate by the addition of electrons.

Video

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

10 Key Terms:

- Autotroph: an organism that obtains organic food molecules without eating other organisms or substances derived from other organisms.

- Heterotroph: an organism that obtains organic food molecules by eating other organisms or substances derived from them.

- Chlorophyll: a green pigment located within the chloroplasts of plants and algae and in the membranes of certain prokaryotes.

- Mesophyll: the ground tissue of a leaf, sandwiched between the upper and lower epidermis and specialized for photosynthesis.

- Stomata: a microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant.

- Stroma: within the chloroplast, the dense fluid of the chloroplast surrounding the thylakoid membrane.

- Thylakoid: a flattened membranous sac inside a chloroplast.

- Photophosphorylation: the process of generating ATP from ADP and phosphate by means of a proton motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis.

- Wavelength: the distance between the crests of electromagnetic waves.

- Electromagnetic spectrum: the entire spectrum of electromagnetic radiation ranging in wavelength from less than a nanometer to more than a kilometer.

Chapter 9: Cellular Respiration Harvesting Chemical Energy

3 Main Questions:

- What is the equation for Cellular Respiration?

C6H12O6 + 6O2 --> 6CO2 +6H2O + Energy(ATP + Heat)

- What are the 3 stages of cellular respiration?

Glycolysis, citric acid cycle, oxidative phosph

orylation: electron transport and chemiosmosis.

- How many ATP glycolysis produces?

2 ATP

5 Main Facts:

- Electrons lose very little of their potential en

ergy when they are transferred from glucose to

NAD+.

- One catabolic process, fermentation, is a partial degradation of sugars that occurs without the use of oxygen.

- The most prevalent and efficient catabolic pathway is aerobic respiration, in which oxygen is consumed as a reactant along with the organic fuel.

- The term cellular respiration includes both

aerobic and anaerobic processes.

- In redox reaction, the loss of electrons from one substance is called oxidation.

Diagram:

This is a methane combustion as an energy-yielding redox reaction. The energy released from the reaction to the surroundings due to the electrons lose potential energy when they end up being shared unequally. They also spending more time around the electronegative atoms sucj as oxygen.

Summary

Living cells require transfusions or energy from outside sources to carry out their function and tasks. In order to finish those tasks, living cell need to run through a few process which includes cellular respiration. Cellular respiration consists of both aerobic and anaerobic processes.

In cellular respiration, glycolysis, citric and cycle, oxidative phosphorylation: electron transport and chemiosmosis are the three main stages. In addition, the electron carrier in cellular respiration is FADH2.

Video

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

10 Key terms:

- Electron transport chain: a sequence o electron carrier molecules that shuttle electrons during the redox reactions that release energy used to make ATP.

- Glycolysis: the splitting of glucose into pyruvate.

- Acetyl CoA: acetyl coenzyme A; the entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme.

- Cytochromes: an ion containing protein that is a component of electron transport chains in the mitochondria and chloroplasts.

- ATP synthase: a complex of several membrane proteins that provide a port through which protons diffuse.

- Chemiosmosis: an energy coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP.

- Alcohol fermentation: glycolysis followed by the conversion of pyruvate to carbon dioxide and ethyl alcohol.

- Latic acid fermentation: glycolysis followed by the conversion of pyruvate to lactate, with no release of carbon dioxide.

- Obligate anaerobe: an organism that only carries out fermentation or anaerobic respiration.

- Facultative anaerobic: an organism that makes ATP by aerobic respiration if oxygen is present but that switches to anaerobic respiration or fermentation if oxygen is not present.