Key Terms_ Chapter 9 to 13

Heredity (inheritance) - transmission of traits from one generation to next

Genetics - the scientific study of heredity

Clone - a group of genetically identical individuals

Gametes - reproductive cells

Somatic cells - any cell other than those involved in gamete formation

Karyotype - display of paired chromosomes (map of chromosomes)

Sex chromosomes - x and y, determine the sex

Autosomes - other chromosomes

Diploid cell - any cell with two chromosome sets (2n)

Haploid cell - any cell with a single chromosome set (n)

Autotrophs – self feeders

Heterotrophs – obtain their organic material by the second major mode of nutrition, unable to make their own food

Chlorophyll – the green pigment within chloroplasts

Mesophyll – the tissue in the interior of the leaf

Stroma – the dense fluid within the chloroplasts

Thylakoids – interconnected membranous sacs

Grana – thylakoid coumn

Photophosphorylation – adition of a phosphate group to ADP

Carbon fixation – initial incorporation of carbon into organic compounds

Wavelength – the distance between the crest of electromagnetic waves

Aerobic respiration – the most relevant and efficient catabolic pathway

Anaerobic – no O₂

Cellular respiration – both aerobic and anaerobic processes

Oxidation – loss of electrons and energy

Oxidizing agent – the electron acceptor

Reduction – gain of electrons and energy

Reducing agent – the electron donor

NAD+ - electron carrier/acceptor, oxidizing agent in glycolisis

Chemiosmosis – energy-coupling mechanism

Fermentation – a way of harvesting chemical energy without using either oxygen or any ETC.

Meiosis and Sexual Life Cycles_Chapter 13

1. How does meiosis differ to mitosis?

2. Differences between asexual and sexual reproduction.

3. What are the sexual sources of genetic variations?

1. Meiosis produces cells there differ genetically from their parent cells. Mitosis produces daughter cells that are genetically identical to their parent cell.

Synapsis and crossing over just occur in meiosis, meiosis 1.

At metaphase 1, chromosomes are positioned on the metaphase as pairs of homologs, rather than individual chromosomes, as in metaphase of mitosis.

At anaphase 1 of meiosis, the replicated chromosomes of each homologous pair move toward opposite poles, but the sister chromatids remain attached. In anaphase of mitosis, by contrast, sister chromatids separate.

2. Individuals reproducing asexually transmit %100 of their genes to their progeny, whereas individuals reproducing sexually transmit %50.

Single parent/two parents. Asexual reproduction requires only mitosis, but sexual reproduction is involved by meiosis.

3.Independent assortment = The random distribution of maternal and paternal homologues to the gametes. Crossing over is another mechanism that increases genetic variation is the process of crossing over, during which homologous chromosomes exchange genes. Random fertilization is another source of genetic variation in offspring.

Video on crossing over: http://www.youtube.com/watch?v=op7Z1Px8oO4&feature=related

5 main facts on this chapter :

. Normal human somatic cells are diploid. They have 46 chromosomes made up of two sets of 23.

. 22 homologous pairs of autosomes, each with maternal and paternal homolog. The 23rd pair is the sex chromosome, determines the sex of the person.

. Three events in sexual reproduction contribute to genetic variation in a population..

. Independent assortment happens in meiosis, crossing over during meiosis I, and random fertilization of egg cells by sperm.

. Meiosis I separates homologous chromosomes, while meiosis II separates sister chromatids.

In this chapter, we learnt about meiosis, its different stages, and differences between meiosis and mitosis. We studied origins of genetic variation among offsprings.

The Cell Cycle_Chapter 12

1. How does the interphase work?

2. What are the phases of Mitotic division?

3. Explain the cell cycle control system?

1. Interphase: Interphase is the period in the cell cycle when the cell is not dividing. During interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size is may increase. Interphase accounts for $90 of the cell cycle. It has three parts. G1,S, and G2. In G1 part, cell grows. In S part, DNA is synthesized, and chromosomes are replicated. In G2 part, cell is prepared for division.

2. After Interphase, the phases are: Prophase, Prometaphase, Metaphase, Anaphase, Telophase and Cytokinesis.

Video on this mitotic cell division:

http://www.youtube.com/watch?v=vh8JAN8vDeA&feature=fvw

http://nobelprize.org/educational_games/medicine/2001/cellcycle.html

3. The cell cycle has interacting proteins that act as stop and go signals at specific points during the cycle. There are two major CHECKPOINTS. One is just before the cell enters the S phase, and the other is before entering Mitosis. If a cell is too small, or starved, or the environment cannot provide the proteins and energy necessary for the division, control proteins will delay the cell's attempt to duplicate itself. (Gzero) G1 checkpoint. p53 prevents cells with damaged DNA from proceeding to the S phase of the cell cycle. The cell can then attempt to repair the DNA and if succesful, go on to S phase. G2 checkpoint provides a safety gap before the cell plunges into Mitosis. The cell ensures that DNA replication is complete. The G2 checkpoint is similar to the G1 checkpoint in that it is a timing point at the end of g2 where STOP proteins can prevent mitosis until the cell has completed all the required steps for division.

5 main facts about the cell cycle:

. Prophase : In early prophase, the centrosomes move toward opposite poles of the cell, organizing the spindle microtubules between them. The sister chromatids become visible in the nucleus as they condense.

. The chromatids remain lined up between the poles of the cell during metaphase.

. Anaphase begins when the pairs of sister chromatids separate. The separated chromatids are now called chromosomes, and move towards the poles of the cell.

. The chromosomes arrive at the pole and the new nuclear membranes form around them in telophase.

. Division of the cytoplasmic components is called cytokinesis. The parent cell divides into two.

Cell cycle occurs in order to reproduce, grow, and repair the cell. The goal if the cell division is to split the sister chromatids and give one to each new cells. Regulation of cell division must be controlled by checkpoints. If the control system fails, the cancer cells occur. They do not stop dividing.

Cell Communication_Chapter 11

1. The three stages of the cell communication?

2. What are the roles of protein kinases and phosphorylation in signal amplification?

3. What are the membrane receptors?

1. a) Reception : this is the first stage. outside of the cell to inside of the cell. receptor is in the membrane, taking in the signal molecules. the signal molecules are mostly water soluble. they are too large to travel thru membranes, they so uses receptors to get in the cell. receptor molecules are made of protein. they are flexible, depending on the signal molecule.

b) Signal Transduction : when the signal molecule moves to cytoplasm from the receptor. there is phosphorylation during this pathway. uses protein kinases which are enzymes that transfers phosphate groups from ATP to a protein.

c) Response : the signals coming from cytoplasm go to the nucleus. proteins turn specific genes on and off.

2. Protein kinases and phosphorylation in signal amplification :

A protein kinase is a kinase enzyme that modifies other proteins by chemically addingphosphate groups to them (phosphorylation). Phosphorylation usually results in a functional change of the target protein (substrate) by changing enzyme activity, cellular location, or association with other proteins. Up to 30% of all human proteins may be modified by kinase activity, and kinases are known to regulate the majority of cellular pathways, especially those involved in signal transduction.Tyrosine-specific protein kinases phosphorylate tyrosine amino acid residues, and like serine/threonine-specific kinases are used in signal transduction.

3. There are three membrane receptors. G Protein -Coupled Receptors, Receptor Tyrosine Kinases, and Ion Channel Receptors. These are located in the plasma membrane.

Video on cell communication :

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

Some facts about cell communication/signaling :

. Many signal transduction pathways include phosphorylation cascades, in which a series of protein kinases each add a phosphate group to the next one in line, activating it.

. Apoptosis, is a type of programmed cell death.

. Intracellular signals are the proteins in the nucleus or in the cytoplasm that can pass thru the membrane without the help of a receptors. ex. hormones.

. Reception may occur by direct contact, or by indirect contact.

. Two results, cytoplasmic regulation, or transcription regulation in the nucleus.

This chapter is about cell communication/ signaling. Cells communicate in order to respond to the environment, and to regulate themselves. Cells need to control cellular processes by signaling. There are three stages and each stage has its own work, and helpers such as enzymes, receptors, signals etc. There are two types of cellular responses, cytoplasmic regulation, and transcription regulation in the nucleus. It can cause a rearrangement of the cytoskeleton, or activation of new protein synthesis.