Structure and Function of the Cell

1
Structure and Function of the Cell

• Chapter 4

2
4.1 Discovering the cell

• 1665 Hooke looked at plants under the
  microscope and saw little boxes
• He named them cells
• 1673 Van Leeuwenhoek was the first to see
  living cells

3
Fast Forward150 years!

• Schleiden all plants are composed of cells
• Schwann all animals are composed of cells
• Virchow cells come only from other cells
• These three scientists work lead to the modern
  CELL THEORY

4
The Cell Theory

• 1. All living things are composed of cells
• 2. Cells are the basic unit of an organism
• 3. Cells only come from the reproduction of
  preexisting cells.

5
Cell Diversity
Red Blood Cells
Bacterial Cells
Parasitic Cell
Ulcer causing bacteria cells
6
Your body has over 200 different types of cells!
7
Cell Size
Most cells are microscopic
Cell size is limited by the surface area
to volume ratio
8
Cell Shape

• Shape is determined by the function of the cell

9
Internal Organization

• Prokaryotic Vs. Eukaryotic Cells

Before Nucleus No Nucleus or Membrane
organelles Single cell organisms
True Nucleus Yes Nucleus and Membrane
organelles Multicellular and single Cell
organisms
10
Surface Area to Volume Ratio

• Surface Area L x W x of sides
• Volume L x W x H
• Ratio surface area/volume

11
Now you try.

1. Obtain a copy of the lab Modeling Cells Surface
   Area to Volume AND box paper
2. Cut out boxes and tape them together (3 boxes
   total)
3. Complete lab worksheet about surface area to
   volume ratio

12
All Eukaryotic Cells Have

1. A cell membrane
2. A nucleus
3. Other organelles

13
Parts of the Eukaryotic Cell
The structures are determined by the functions of
each part
14
1. Cell Membrane

• Function outer layer of a cell that allow
  substances into and out of the cell
• Selectively permeable allows only certain
  things to cross the membrane

15
(No Transcript)
16
Parts of the Membrane

• Membrane Lipids
• Phospholipids arranged due to their hydrophobic
  and hydrophilic ends
• Lipid bilayer
• Steroid (cholesterol) embedded within

17
Parts of the Membrane (cont)

• Membrane Proteins
• Peripheral proteins attached to either side of
  the cell membrane
• Integral proteins embedded within the cell
  membrane and extends out on both sides

18
Fluid Mosaic Model

• Membrane behaves like a liquid
• Lateral movement of lipids and proteins
• Mosaic changing pattern of proteins and lipids
  in the membrane

19
Organelles

• Mini organs of the cell
• Each organelle has its own structure and function
• All cells have different types and numbers of
  organelles

20
Nucleus

• Function to store the hereditary information of
  the cell (DNA) and to control the cell
• Contains nuclear envelope, nuclear pores,
  nucleolus, and chromatin (chromosomes)

21
Mitochondria

• Function makes ATP
• Powerhouse of the Cell

22
Rough Endoplasmic Reticulum

• Function Makes proteins, glycoproteins, and
  membranes for export out of the cell
• Covered in ribosomes

23
Smooth Endoplasmic Reticulum

• Function Makes lipids, metabolizes
  carbohydrates, and detoxification center for the
  cell

24
Ribosomes

• Function Protein synthesis
• Attached to E.R. or free in cytoplasm
• Made in nucleus and completed in cytoplasm

25
Golgi Apparatus

• Function Manufacturing, warehousing, sorting,
  and shipping materials out of the cell

26
Lysosomes

• Function Digests (breaks down) macromolecules
  the are in the cell, such as proteins and carbs.
• Also breaks down dead cells

27
Peroxisomes

• Function Breaks down fatty acids
• Detoxification center in liver cells

28
Cytoskeleton

• Function Support system of the cell, aid in
  movement within the cell
• 3 Structural Types
• microtubules
• microfilaments
• intermediate filaments

29
Cytoplasm

• Function Holds organelles in the cell
• Site of all chemical reactions in cell

30
Cilia and Flagella

• Function Locomotion and movement of materials
  around the cell
• Animal cells only

31
Cell Wall

• Function Protects the cell, gives the cell
  shape and structural support
• Plant cells

32
Chloroplasts

• Function Photosynthesis
• Makes energy from the sun
• In plant cells

33
Central Vacuole

• Function Stores materials especially water and
  waste products
• In plant cells