1. Cell Structure and Function
I will explain what the cell theory is
I will describe how researchers explore the living cell
I will distinguish between eukaryotes and prokaryotes

2. Cell Theory ALL living things are composed of cells
Cells are the basic units of
Structure
Function
in living things
New cells are produced from existing cells

3. Cell Theory Single Cell Organisms Multicellular Organisms
Many of the cells are specialized to do particular jobs

4. Two Cell Types Prokaryotic Cells Eukaryotic Cells
Have genetic material that is NOT contained in the nucleus
Eukaryotic Cells
Have genetic material that IS contained in the nucleus (separated from rest of cell)

5. Two Cell Types Prokaryotes many diverse forms, including all bacteria
thought to be the oldest forms of life
most do not have internal membranes (no compartments)
small in size ( micrometers)
found in Domain Archaea and Domain Bacteria (page 1072)

6. Two Cell Types Eukaryote
DO have internal membranes; they posses compartments surrounded by membranes called organelles
larger in size ( micrometers)
found in Domain Eukarya (pages )

7. Eukaryotic Cell Structure
organelle: cell structures that have special functions (jobs)
cytoplasm: everything between the plasma membrane and the nucleus
cytosol: the fluid portion of the cell; more jellylike than water like because there are many sugars and proteins and minerals, etc. dissolved in this fluid

8. Nucleus
Nuclear Pore
Nuclear Membrane
Nucleolus
Chromatin

9. Nucleus Nucleus (Nuclei = plural)
a round body surrounded by two membranes
contains hereditary material and nucleoli
Controls the activities of the cell
Nuclear Envelope:
two membranes surrounding the nucleus
isolates the DNA from the rest of the cell.
Nuclear Pores:
holes in the envelope
allows messages to enter and leave the nucleus.
Nucleolus: (Nucleoli = plural)
spherical structure inside the nucleus.
assembles the pieces that make up ribosomes.
Chromatin = Hereditary material:
DNA of cell
instructions that tell the cell what proteins to create; proteins (enzymes) control the activities of the cell.
Each individual strand of DNA in a nucleus is called a chromosome. Chromosomes become visible with a light microscope when a cell divides because they condense.
All the chromosome strands within a nucleus = chromatin.

12. Ribosomes

13. Ribosomes very small, dot like, even in electron microscope photos.
found in all cells including prokaryotes, extremely numerous.
where proteins are assembled.
most float free in the cytoplasm, some are attached to membranes

14. Endoplasmic Reticulum

15. Endoplasmic Reticulum
a complex network of membranes that form flattened sheets, sacs, and tubes that tend to lie parallel to one another.

16. Endoplasmic Reticulum
they synthesize and transport lipids and proteins.
attached to both plasma and nuclear membranes.
RER = rough endoplasmic reticulum = has attached ribosomes for synthesis of proteins
SER = smooth endoplasmic reticulum = no attached ribosomes; contains enzymes to perform special tasks such as synthesizing lipids and detoxifying drugs

17. Golgi Apparatus

18. Golgi Apparatus
membranes organized as a series of closely stacked flattened sacs.
receives, modifies, sorts, and packages proteins/lipids from endoplasmic reticulum.
cells that secrete hormones, enzymes, and other proteins are loaded with Golgi apparatus

19. Lysosome

20. Lysosome Typically only in animal cells
small organelle; contains digestive enzymes
removes "junk" from the cell
breakdown lipids, carbohydrates, proteins and cell organelles that have outlived their usefulness
merge with food vacuoles to digest food
merge with bacteria to break down bacteria

21. Vacuole

22. Vacuole spherical membrane bound organelle.
stores water, minerals, salts, proteins and carbohydrates
in most mature plant cells it takes up most of the central portion of the cell
single celled freshwater organisms often contain a specialized vacuole called a contractile vacuole.
pumps excess water out of the cell. (another example of homeostasis)

23. Mitochondria

24. Mitochondria oval or rod shaped structures
composed of an inner and an outer membrane
inner membrane has many folds (cristae) which increases the surface area of the inner membrane
the cells powerhouse
contain enzymes that split sugar molecules (glucose) and transfer the energy to other molecules (ATP) that the cell can use
this process is called cellular respiration

25. Chloroplast

26. Chloroplast oval shaped structure
composed of an inner and an outer membrane
the inner membranes, thylakoids, are arranged in stack like layers called grana

27. Chloroplast
chlorophyll (green pigment) and all the enzymes necessary to convert light energy, carbon dioxide, and water into chemical energy (sugars) in a process called photosynthesis is packed within the thylakoids
all chloroplasts have their own DNA
Lynn Margulis, an American biologist, proposed in 1970 that mitochondria and chloroplasts are actually the descendents of prokaryotes that took up a symbiotic relationship in eukaryotic cells. This idea is called the endosymbiotic theory.

28. Centriole

29. Centrioles
two small organelles near the nucleus (at right angles to each other)
microtubules made of tubulin
organizes cell division

30. Cytoskeleton
a network of protein microtubules and microfilaments that help maintain shape and are involved in movement within the cell
microtubules: hollow tubes of tubulin that maintain cell shape

31. Cytoskeleton
microfilaments: threadlike actin fibers, which can contract (shorten) and therefore change the shape of the cell, move cytoplasm, and provide a framework that is flexible, yet supports the cell.