Chapter 5 Cell Growth and Division

5.1 The Cell Cycle

Cycle=repetition or repeating patterns.

G0 (Gap 0): cells carry out their normal functions but are unlikely to divide ex: Neurons

1. gap 1 
2. cell growth, normal functions, replications of organelles, length of time a cells varies for each cell & organism. Critical check point in cell division #1 @ the end of G1. 
3. synthesis. 
4. copies DNA from the nucleus
5. gap 2 
6. more growth and normal functions, Critical check point in cell division #2 @ the end of G2.
7. mitosis 
8. cell division 
9. prophase 
10. metaphase 
11. anaphase 
12. telophase 
13. cytokinesis   Cyto=Cell    Kinesis=division
14. mitosis 
15. interphase 

Cells divide at different rates: 

• Rates of cell division vary widely
• Cell divides according to the body’s need (Ex. Skin cells divide more often then liver cells.) 
• The length of gap 1 varies widely among cell types. 
• Neurons, enter a stage called G0, where cells are unlikely to divide again.

Cell size is limited due to surface to volume ratio:

• If cell is small it could not contain organelles and needed molecules. 
• If cells is large it could not move enough materials across the membrane surface. 
• To be at perfect size cell growth and division must be coordinated.

Experiment Explaining The Importance of Size of Cell

G1& G2 stages got their names because scientists did not see any activity going on in cells, and thought there were Gaps in cell activity. 

M-Phase (Mitosis): Cells The cell nucleus and its contents divide this includes cytokinesis.


Division and Growth must coordinate for cells to stay the same size from generation to generation.

What Breast Cancer Cells Look Like When Dividing

5.2 Mitosis & Cytokinesis

Chromosome structure

• A chromosome is one long continuous thread of DNA. 
• DNA wraps around proteins called histones. 
• During Interphase,DNA and histones form chromatin that look like spaghetti.
• Chromosomes condense tightly for mitosis.
• Because they are duplicated, they look like an X. 

1.interphase: copies DNA, grows, duplicates organelles 
2. prophase: chromosomes condense, nuclear envelope breaks down, spindle fibers form. 
3. metaphase: spindle fibers align chromosomes along the cell equator 
4. anaphase: chromatids separate to opposite sides of cell 


5. telophase: nuclear membranes start to form around chromosomes, chromosomes begin to uncoil, spindle fibers fall apart 
6. cytokinesis: divides the cytoplasm between two daughter cells 

Say What?? Let's see it again!

Microscope Project Launch

Poorest cities: Brownsville, Texas: A man stands out of the wind during a downpour in downtown Brownsville.

According to U.S. Census Bureau data and economic website 24/7 Wall St., two of the poorest cities in the nation are in Texas.

Data shows that the Brownsville-Harlingen area has overtaken McAllen as the poorest city in the country, putting them in the first and second spots.

Of the Brownsville-Harlingen area's 415,557 residents, 36 percent live below the poverty level. Texas' overall poverty rate is 17 percent. In Brownsville, 22 percent of the population has only a high school diploma or other equivalent certificate. 37 percent do not have a high school diploma.

You have been hired by BASF The Chemical Company which is a global leader in manufacturing products for various industries which include aerospace, agriculture, automotive, packaging, personal care, and pharmaceutical among others. As an employee of BASF, you will be responsible for designing, creating, and testing an economical cell phone accessory that will allow you to examine various types of cells on the go using materials easily attainable by others. The cost of your product should be no higher than $10 dollars. Remember that the product you are developing will be tested in real life applications. Document all activity throughout the project. You are given a deadline of 3 weeks. ALL members are to be involved throughout the development of the project.

Product Name:__________________________________________________

Product Designer:_______________________________________________

Product Engineer:_______________________________________________

Manufacturing:________________________________________________

Product Presenter/Marketer:_____________________________________

A brief look at microscopes from the past...

Content Standards

B.5.B   examine specialized cells, including roots, stems, and leaves

of plants; and animal cells such as blood, muscle, and

epithelium

B.1.A demonstrate safe practices during laboratory and field investigations

B.1.B demonstrate an understanding of the use and conservation of resources and the proper disposal or recycling of materials

B.2.H communicate valid conclusions supported by the data through methods such as lab reports, labeled drawings, graphic organizers, journals, summaries, oral reports, and technology‐based reports

B.3.A in all fields of science, analyze, evaluate, and critique scientific explanations by using empirical evidence, logical reasoning,

and experimental and observational testing, including examining all sides of scientific evidence of those scientific explanations, so as to encourage critical thinking by the student

B.3.B communicate and apply scientific information extracted from various sources such as current events, news reports, published

journal articles, and marketing materials

Chapter 4.4 & 4.6

Making Connections: 

 If chloroplasts are like tiny factories that make products, 

mitochondria are like power plants that burn fuel to produce electricity. 





In a power plant, a processed fuel is burned in the presence of oxygen, and energy is released as useful electricity. 

During cellular respiration, oxygen and digested molecules from food are used to produce useful energy in the form of ATP.

4.4 Overview of Cellular Respiration

Cellular respiration—process through which sugars and other carbon-based molecules are broken down to produce ATP when oxygen is available

Glycolysis—anaerobic process in cytoplasm that splits glucose into 2 three-carbon molecules

1. mitochondrion 

2. Pyruvate: three-carbon molecules

3. Krebs cycle; mitochondrial matrix; produces 2 ATP 

4. carbon dioxide 

5. energy transferred to 2nd aerobic stage 

6. energy from glycolysis and oxygen enter the process 

7. Electron Transport chain: produces water and 
large number of ATP  (34)

Cellular respiration equation: 







C6H12O6 + 6O2 ⇒⇒⇒⇒⇒⇒6CO2 + 6H2O

Kreb Cycle:produces molecules that carry energy to the second part of cellular respiration

Recap Questions: 

1.Compare Describe the relationship between cellular respiration and photosynthesis in terms of energy and matter.

2. Is oxygen necessary for the production of all ATP in your cells? Why or why not?

4.6 Fermentation 

Making Connections:

Think about a time when you worked or exercised hard. Maybe you moved heavy boxes or furniture. 

Maybe, playing basketball, you found yourself repeatedly running up and down the court. 

Your arms and legs began to feel heavy, and they seemed to lose strength. 

Your muscles became sore, and even when you rested you kept breathing hard. Your muscles were using fermentation

Fermentation—process that allows glycolysis to continue to produce ATP when oxygen is not available, but does not produce ATP

Lactic acid fermentation—pyruvate and NADH enter fermentation; NADH used to convert pyruvate into lactic acid; NAD+ recycled to glycolysis

Alcoholic fermentation 
—pyruvate and NADH enter fermentation; NADH used to convert pyruvate into an alcohol and carbon dioxide; NAD+ recycled to glycolysis

Uses of Fermentation:

1. cheese                                                      2. yogurt

3. bread

Recap Questions:

1. How are lactic acid fermentation and alcoholic fermentation similar? How are they different?

2. Describe the similarities and differences between cellular respiration and fermentation. 

Quiz Chapter 4.4&4.6