Cell Processes and Energy Photosynthesis Respiration Cell Division Cancer Table of Contents.

Cell Processes and Energy

Photosynthesis

Respiration

Cell Division

Cancer

Table of Contents

Cell Processes and Energy - Photosynthesis

Sources of Energy

Nearly all living things obtain energy either directly or indirectly from the energy of sunlight captured during photosynthesis.


The Photosynthesis Process Activity

Click the Active Art button to open a browser window and access Active Art about the photosynthesis process.

- Photosynthesis

Cell Processes and Energy - Photosynthesis

The Two Stages of Photosynthesis

During photosynthesis, plants and some other organisms use energy from the sun to convert carbon dioxide and water into oxygen and sugars.


SequencingSequence is the order in which the steps in a process occur. As you read, create a flowchart that shows the steps in photosynthesis. Put each step in a separate box in the flowchart in the order in which it occurs.

Steps in Photosynthesis

Sunlight strikes leaf.

Chlorophyll captures light energy.

Cells use the energy to produce sugars and oxygen from water and carbon dioxide.

- Photosynthesis


Photosynthesis

Click the Video button to watch a movie about photosynthesis.

- Photosynthesis


End of Section:Photosynthesis

Cell Processes and Energy - Respiration

Two Stages of Respiration

During respiration, cells break down simple food molecules such as sugar and release the energy they contain.

Cell Processes and Energy - Respiration

Photosynthesis and Respiration

You can think of photosynthesis and respiration as opposite processes.


Using Prior KnowledgeYour prior knowledge is what you already know before you read about a topic. Before you read, write a definition of respiration in a graphic organizer like the one below. As you read, revise your definition based on what you learn.

Respiration is when an organism breathes in oxygen because oxygen is needed by cells.

Respiration also means the process in which cells break down simple food molecules such as sugar and release the energy they contain.

- Respiration

What You Know

What You Learned


Respiration

Click the Video button to watch a movieabout respiration.

- Respiration


Links on Cellular Respiration

Click the SciLinks button for links on cellular respiration.

- Respiration


End of Section:Respiration

Cell Processes and Energy - Cell Division

Mitosis

During mitosis, the cell’s nucleus divides into two new nuclei. One copy of the DNA is distributed into each of the two daughter cells.


The Cell Cycle


Cell Cycle Activity

Click the Active Art button to open a browser window and access Active Art about the cell cycle.

- Cell Division


Length of the Cell Cycle

How long does it take for a cell to go through one cell cycle? It all depends on the cell. A human liver cell, for example, completes one cell cycle in about 22 hours, as shown in the graph. Study the graph and then answer the following questions.

- Cell Division



The longest curved arrow represents the cell’s interphase; the shortest represents cytokinesis; and the middle one represents mitosis.

Reading Graphs:

What do the three curved arrows outside the circle represent?

- Cell Division



Interphase

Reading Graphs:

In what stage of the cell cycle is the wedge representing growth?

- Cell Division



10 hours

Interpreting Data:

In human liver cells, how long does it take DNA replication to occur?

- Cell Division



Interphase

Drawing Conclusions:

In human liver cells, what stage in the cell cycle takes the longest time?

- Cell Division


Structure of DNA

The DNA molecule is shaped like a twisted ladder.


Replication of DNA

Because of the way in which the nitrogen bases pair with one another, the order of the bases in each new DNA molecule exactly matches the order in the original DNA molecule.


SequencingAs you read, make a cycle diagram that shows the events in the cell cycle, including the phases of mitosis. Write each even in a separate circle.

The Cell Cycle

Cell grows, makes a copy of DNA.

Chromosomes and spindle fibers form; nuclear

envelope breaks down.

Chromosomes line up across the center and attach

to a spindle fiber.Centromeres split;

chromatids separate and move to opposite ends.

Chromosomes stretch out; new nuclear envelope forms

around chromosomes.

Cell pinches in two; each daughter cell has same number

of identical chromosomes.

- Cell Division


End of Section:Cell Division

Cell Processes and Energy - Cancer

What Is Cancer?

Cancer is a disease in which cells grow and divide uncontrollably, damaging the parts of the body around them.


Previewing VisualsWhen you preview, you look ahead at the material to be read. Preview Figure 17. Then write two questions you have about the illustrations in a graphic organizer like the one below. As you read, answer your questions.

Q. What is a tumor?

A. A mass of abnormal cells that develops when cancerous cells divide and grow uncontrollably.

Q. How does cancer spread?

A. Some of the tumor cells can break off and enter the bloodstream.

How Cancer Spreads

- Cancer


Links on Cancer

Click the SciLinks button for links on cancer.

- Cancer


End of Section:Cancer


Graphic Organizer

Comparing Photosynthesis and Respiration

Feature

Oxygen and sugars

Photosynthesis Respiration

Raw materials

Products

Is energy released?

Water and carbon dioxide

Yes

Oxygen and sugarsWater and carbon dioxide

No


End of Section:Graphic Organizer

Cell Processes and Energy Photosynthesis Respiration Cell Division Cancer Table of Contents.

Documents

Transcript of Cell Processes and Energy Photosynthesis Respiration Cell Division Cancer Table of Contents.