1. Chapter 7 Cell Structure and Functions

2. Chapter Outline 7-1 Life is Cellular 7-2 Eukaryotic Cell Structure
7-3 Cell Boundaries
7-4 The Diversity of Cellular Life

3. Microscopes and Scientists
Robert Hooke
used compound microscope to look at cork (dead wood)
called small chambers “cells”
2. Anton Van Leeuwenhoek: used single lens microscope & saw tiny organisms in pond water

4. Microscopes and Scientists
3. Mathias Schleiden: concluded that plants are made of cells
4. Theodore Schwann: concluded that animals are made of cells
5. Rudolph Virchow: stated cells come from existing cells

5. The Cell Theory All living things are composed of cells.
Cells are the basic units of structure and function in living things.
New cells are produced from existing cells.

6. Exploring the Cell 1. Electron microscopes
Samples are put in a vacuum… must be dead
Transmission electron microscopes (TEM): beams of electrons are
passed through a thin sample
Scanning electron microscope (SEM): beam of electrons move over the surface of a sample

7. Prokaryotes and Eukaryotes
1. All cells have a cell membrane and contain DNA
2. nucleus: a large structure that contains the cell’s genetic material in the form of DNA
3. Prokaryotes: cells that do not contain a nucleus
Small and simple cells
Bacteria are prokaryotes

8. Prokaryotes and Eukaryotes
4. Eukaryotes: cells that contain a nucleus
Large and complex cells; Highly specialized
Can be unicellular (one celled organism) or multicellular
Plants, animals, fungi and protists are eukaryotes
Cell membrane
Cytoplasm
Cell membrane
Prokaryotic Cell
Eukaryotic Cell
Cytoplasm
Nucleus
Organelles

9. Cell Organelles
1. Eukaryotic cells contain organelles: specialized structures that perform functions within the cells
2. Cytoplasm
portion of cell outside the nucleus
3. Nucleus
control center of the cell
4. Chromatin
DNA bound to protein
5. Chromosomes
condensed form of chromatin seen during division

10. Cell Organelles 6. Nucleolus
dense region in nucleus where ribosomes are made
7. Ribosomes
make proteins with instructions from the nucleus
8. Endoplasmic Reticulum
site where lipids, proteins and other materials are made; two types- smooth and rough
9. Golgi Apparatus
modifies, sorts, and packages proteins and materials
10. Lysosomes
organelle filled with enzymes that breakdown wastes

11. Cell Organelles 11. Vacuoles
structure that stores water, salts, proteins, and carbs
12. Mitochondria
convert energy from food into compounds the cell can use
13. Cloroplast
capture energy from sunlight and covert to chemical energy
14. Cytoskeleton
network of proteins that maintains cell shape and helps in cell movement
15. Centrioles
organelle that helps in cell division in animal cells

12. Do now – vocab review ________________ = basic unit of life
________________ = DNA bound to protein
________________ = cells that contain a
nucleus
________________ = specialized structures found in some cells
________________ = mass of solute in a given
volume of solution

13. Bonus Question
What is the term that describes the movement of the smell of popcorn?

14. Cell Boundaries
Cell membrane: thin flexible barrier that regulates what enters and leaves the cell.
1. Most cell membranes have a lipid bilayer
2. Contain proteins and carbohydrates
Outside
of cell
Inside
(cytoplasm)
Cell
membrane
Proteins
Protein
channel
Lipid bilayer
Carbohydrate
chains

15. Lipids and water

16. Cell Boundaries Cell Wall: provides support and protection
Nuclear
envelope
Ribosome
(attached)
(free)
Smooth endoplasmic
reticulum
Nucleus
Rough endoplasmic reticulum
Nucleolus
Golgi apparatus
Mitochondrion
Cell wall
Cell
Membrane
Chloroplast
Vacuole
Plant Cell
Cell Boundaries
Cell Wall: provides support and protection
1. Present in plants, algae, fungi and many prokaryotes
2. Cell walls lie outside the cell membrane
3. Composed mostly of a carbohydrate called cellulose

17. Diffusion through boundaries
1. concentration = mass of solute in a given volume of solution
Ex: 12 g salt in 3L water = 4g/L
2. diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration
3. equilibrium: when concentration of solute is same throughout area

18. Diffusion video

19. Diffusion visual
website

20. Osmosis
4. Osmosis: diffusion of water across a selectively permeable membrane
Water can move across the membrane, and many solutes cannot

21. Osmosis Terms for concentrations on sides of a membrane
Isotonic: concentration is same on both sides
Hypertonic: concentration of solute is higher
Hypotonic: concentration of solute is lower
Cells are usually near isotonic solutions, so that they do not burst

23. 5. Facilitated Diffusion: protein gates help certain molecules diffuse
Glucose
molecules
High
Concentration
Cell
Membrane
Protein
channel
Low
Concentration

24. 6. Active transport: uses energy to move molecules from an area of low concentration to high concentration
Animation
Normally cells have a lower Na+ concentration than outside. To keep it that way, cells have to pump Na+ out of the cell.
Molecule to
be carried
Molecule
being carried
Energy

25. Exocytosis: process of releasing materials
Endocytosis: process of taking material into cells by forming a pocket of cell membrane
Phagocytosis – surrounding food particles
Pinocytosis – surrounding liquids
Exocytosis: process of releasing materials

26. Review of Cell transport
Wiley.com

27. Label the organelles

28. Unicellular vs. Multicellular
1. unicellular organisms: one-celled organism: yeast, volvox aureus
2. multicellular organisms
Cell specialization: cells throughout an organism can develop in different ways to perform different tasks
Specialized animal cells
Red blood cells – carry oxygen throughout body
Pancreatic cells – many ribosomes to make proteins and enzymes for digestion
Muscle cells – overdeveloped cytoskeleton

29. Multicellular organisms
Levels of organization (Individual organism)
Cellstissuesorgansorgan systems
Muscle cell
Smooth muscle tissue
Stomach
Digestive system