1. Learning about the building blocks of life
Unit 5 - Cells
Learning about the building blocks of life

2. What are cells?
Definition: - the basic unit of life that performs life functions for the organism Every living thing is made of cells!!! Unicellular (one cell) Ex. bacterium Multicellular (many cells) Ex. dog
Robert Hooke

3. Cell Theory All living things are made of cells.
Cells are the basic unit of structure and function.
Cells come from other cells.

4. Cell parts
Cells have small tiny structures inside that have specific jobs (like mini organs)
called organelles and float in the cell, much like fruit in Jello

5. Basic Animal Cell Model
(cytoplasm)

6. Basic Plant Cell Model

7. Cell organelles 1. Cell membrane
Have receptor molecules (allow cells to communicate with one another)
Controls what goes in/out of cell; exchanges materials
Keeps shape of cell

8. Cell Organelles Cell Membrane Continued: Receptor Molecules:
Bind to messengers (hormones, molecules) from other cells
Allow cells to ‘communicate’ with one another to maintain homeostasis (internal stability)
Chemical Messengers

9. Cell Parts 2. Cell Wall (plants) 3. Nucleus (has a nucleolus)
Made of cellulose; gives cell shape and protection
Plants have both a cell wall and cell membrane
Control center of the cell; holds chromosomes (DNA is the protein recipe)

10. Cell Parts 4. Chromosome 5. Cytoplasm
Contains coiled DNA (genetic info) found in nucleus; code to make proteins
Jellylike material inside cell that holds organelles in place; like Jello

11. Cell Parts 6. Mitochondria
‘Little engines of the cell’; cellular respiration (energy production) happens here; powerhouse
Glucose (sugar) made into energy (ATP)
Sperm Cell:
Tons of mitochondria to help sperm with long trip to the egg cell

12. Cell Parts 7. Endoplasmic Reticulum 8. Ribosomes
Transport system of cell; moves protein; like a highway
Rough has ribosomes attached, smooth has none
Make (synthesize) proteins from amino acids; gets the recipe (code) from DNA in nucleus

13. Cell Parts 9. Vacuole 10. Chloroplast (plants)
Storage of waste, food, water
Small in animals and large in plants
Site of photosynthesis; contains chlorophyll (green pigment)

14. Cell Parts Chloroplast continued: Photosynthesis Reaction:
Needed Produced
Carbon Dioxide + Water Glucose + Oxygen + Water
*Then, the glucose can be used for cellular respiration in both plant and animal cells
Sunlight

15. Cell Parts 11. Golgi apparatus 12. Lysosome (Animal Cells)
Packages proteins for transport (like UPS)
Looks like stack of pancakes
Breakdown and recycling center (has enzymes)

16. Label the Animal Cell

17. Cell Type Examples
Stained Cheek Cells
Red Blood Cells
Nerve Cells

18. How do molecules get into and out of a cell
Active vs. Passive Transport:
Active
Requires energy (ATP) to move molecules
Often from low to high concentration (walking uphill) or molecules are large
Passive
Does not require energy
Moves molecules from high to low concentration (going downhill)

19. How do things pass in/out of the cell?
Remember, the cell membrane controls what comes in and out of cell (even bad stuff can get in!)
Examples of Passive Transport:
Diffusion - molecules moving from high concentration to low concentration
ex. Perfume spray, balloon demo
Osmosis - water moving from high concentration to low concentration across a membrane
ex. Cup O’ Noodle Soup

20. How do cells make more of themselves?
To make more body type cells, use: mitosis – making an exact copy of body type cells such as skin, blood cells, etc. to grow and repair. To make more sex type cells, use: meiosis - producing sex cells for reproductive purposes; eggs and sperm (have ½ the number of chromosomes)

21. Mitosis in Humans
First, parent cell info is all copied so 46 chromosomes now become 92 chromosomes
Parent cell then divides evenly in two, to create 2 cells with 46 chromosomes each
Parent cell (46 chromosomes)
Parent cell (92 chromosomes)
Daughter cells
(46 chromosomes each)

22. Mitosis in Humans Interphase –
Cell is not dividing (growing, doing cell activities)
DNA will replicate (double)

23. Phases of Mitosis 1. Prophase DNA condenses into organized chromosomes
Nucleus disappears

24. Phases of Mitosis 2. Metaphase
Replicated chromosomes line up down Middle of cell

25. Phases of Mitosis 3. Anaphase
Replicated chromosomes split away-move apart to opposite sides of cell

26. Phases of Mitosis 4. Telophase and Cytokinesis Nucleus comes back
Chromosomes uncoil
Cytoplasm splits = 2 new identical cells

27. END RESULT OF MITOSIS!! Don’t Forget:
Mitosis results in 2 new IDENTICAL body-type cells!!!! 46 46 46

28. Name that Phase 2. 1.
Anaphase
telophase 3. 4.
Prophase
metaphase

29. Meiosis in Humans
The cells responsible for making sex cells (sperm/egg) first replicate their DNA. (46  92)
The replicated DNA is then divided into two cells. (46 chromosomes in each cell)
The two cells further divide to create a total of four cells by the end.
Cells at the end have only 23 chromosomes; not the normal 46.
Parent cell (46 chromo)
Parent cell (92 chromo)
New cells (46 chromo each)
Daughter cells (23 chromo each)

30. Mitosis vs. Meiosis in Humans
Parent cell has 46 chromosomes
(23 prs)
Daughter cell has 46 chromosomes
Get 2 identical cells at end
Cells are “diploid”; chromosomes occur in pairs
Meiosis
Parent cell has 46 chromosomes
(23 prs)
Daughter cell has 23 chromosomes
(NO PAIRS)
Get 4 cells at the end (sperm or egg)
Cells are “monoploid”; cells have half the # of chromosomes

31. What do you think happens when cells can’t stop dividing?
Most of the time, cells are not dividing, instead they are just performing cell activities.
When a cell abnormally divides – it doesn’t get the message to stop – this results in cancer.
Cancer is uncontrolled cell division

32. Cell Organization
Cells
Tissue
Organs
Organ Systems
Organism