Cell Growth and Division

Cell 1: 0.00002 m0.00002 m= 0.02 mmSA= L x W x # of sides

0.02 mm x 0.02 mm x 6 0.0004 x 60.0024 mm2

V=L x W x H0.02 mm x 0.02 mm x 0.02 mm0.000008 mm3

SA:V=0.0024: 0.0000081:300

Cell 2: 0.001 m

0.001 m= 1 mmSA= L x W x # of sides

1 mm x 1 mm x 6 1 x 66 mm2

V=L x W x H1 mm x 1 mm x 1 mm1 mm3

SA:V=6:1

Cell 3: 2.5 cmSA= L x W x # of sides

2.5 cm x 2.5 cm x 6 6.25 x 637.5 cm2

V=L x W x H2.5 x 2.5 x2.515.625 cm3

SA:V= 37.5:15.6252.4:1

Cell 4: 30 cm

SA= L x W x # of sides30 cm x 30 cm x 6 900 x 65400 cm2

V=L x W x H30 x 30 x 3027000 cm3

SA:V= 5400:270001:5

Cell 5: 15 m

SA= L x W x # of sides15 cm x 15 cm x 6 225 x 61350 cm2

V=L x W x H15 cm x 15 cm x 15 cm 3375 cm3

MINILAB

Analysis:1. the ability of a cell to take in

nutrients and get rid of wastes2. More standard sized Cells

Cell Growth

Limits of Cell Growth1. the ability of a cell to take in nutrients and get rid of wastes2. DNA cannot make RNA fast enough to keep up with the cell’s needs

Example 1: cube surface area vs. volumeCells undergo cell division to solve these problems

Cell Growth

Surface area: Length x Width x number of sides

Volume: Length x Width x Height

Surface Area to Volume RatioSurface area : Volume

Quick Activity

1. Cube is 8 cm in diameter, what is the surface area: volume ratio?

2. You have a cuboid with a length of 5 mm, width of 3 mm, and height of 4 mm. What is the surface area: volume ratio?

answers

1. SA:V• SA= 8 x 8 x 6= 384• V=8 x 8 x 8=512• SA:V=384:512 (3:4)

2. SA:V• SA= 5 x 3 x 6= 90• V=5 x 3 x 4=60• SA:V=90:60 (3:2)

Surface Area to Volume Problem

Volume increases much more rapidly than Surface Area it will cause ratio of surface area to volume to decrease

Ex: Small town with two main streets that is growth

Effect of SA: Volume Ratio

Effect of Surface Area to Volume Ratio

Cell Growth

Cell Division: the process whereby the cell divides into two daughter cells

Cell Growth

Rates of cell growthCells can grow very quickly!

Example: E. Coli (a bacterium) can double its volume and divide every 30 minutes.

Cell Growth

Controls on cell growthCells know when to stop, such as when they contact other cells.

Uncontrolled cell growthCancer cells grow and divide until they run out of nutrients.

Cell Division

Two main stages1. Mitosis: the process by which the nucleus of the cell divides into two nuclei, each with the same genetic information as the parent cell.

Cell Division

Two main stages2. Cytokinesis: the process by which the cytoplasm divides, thus forming two distinct cells.

Chromosomes

Chromosomes

Chromosomes contain the genetic information that is passed from one generation to the next.Chromosomes are made of chromatin.

Chromosomes

Chromatin is made of DNA and protein.

Chromosomes

Histones are proteins that help DNA to coil tightly.

Chromosomes

Chromatids: two identical parts of the chromosome.

Centromere: binds chromatids together

Cell Cycle

Cell cycle: the period from the beginning of one mitosis to another.Events of the cell cycle:

1. Interphase2. Mitosis3. Cytokinesis

Cell Cycle

Interphase: period between cell divisions; time of intense activity by the cell.

G1 phase: cell growth and developmentS Phase: DNA replication G2 Phase: shortest; synthesis of organelles and materials

Cell Cycle

Cell Cycle

Mitosis: process by which the nucleus of the cell is divided into two nuclei.

Metaphase

Anaphase

Telophase

Cell Cycle

Prophase:1. Chromosomes appear (chromatin condenses and coils)2. Centrioles separate and move to opposite sides of the nucleus.3. Chromosomes attach to spindle fibers.4. Nucleolus disappears and nuclear envelope breaks down.

Cell Cycle

Metaphase:1. Chromosomes line up across center (equator) of cell.2. Microtubules connect centromeres to poles of spindle.

Cell Cycle

Anaphase:1. Centromeres split; sister chromatids separate.2. Spindle gets longer.3. Chromosomes go to poles.

Cell Cycle

Telophase:1. Chromosomes uncoil into chromatin.2. Nuclear envelope reforms, spindle breaks down, nucleolus becomes visible.

Cell Cycle

Cytokinesis: process by which cytoplasm divides, thus forming two distinct cells.

Pop Quiz

1. What are the 3 events of the cell cycle?

2. What are the stages of interphase?

3. What are the stages of mitosis?

4. What is cytokinesis?

1. What are the 3 events of the cell cycle?1. Interphase, mitosis, & cytokinesis

2. What are the stages of interphase?1. G1, S, & G 2 phase

3. What are the stages of mitosis?1. Prophase, metaphase, anaphase, &

telophase4. What is cytokinesis?

1. The division of the cytoplasm resulting in 2 identical daughter cells

Pop Quiz

1. What happens doing each stage of interphase?

2. What happens doing each phase of mitosis?

3. When do cells stop dividing?