1. Cell Structure and Function
1. The Cell Theory
A. All organisms composed of one or more cells
B. Cell is smallest living organizational unit
C. Cells arise only from division of other cells

2. Attributes of cells A. Plasma membrane B. DNA C. Cytoplasm
D. Obtain energy and nutrients from their environment

3. Cell Size 1–100µ Cell Size A. Limitations of molecular diffusion
1. Faster passage through small cell
2. More efficient communication
B. Limitations of surface-to-volume ratio
1. With increase in size, greater increase in volume than surface area
a. Interaction with outside occurs only at surface
b. Insufficient exchange of materials at plasma membrane for survival

4. diameter of DNA double helix
tallest trees
adult human
chicken egg
frog embryo
most eukaryotic cells
mitochondrion
Figure: 04-01
Title:
Relative sizes.
Caption:
Dimensions commonly encountered in biology range from about 100 meters (the height of the tallest redwoods) through a few micrometers (the diameter of most cells) to a few nanometers (the diameter of many large molecules).
most bacteria
virus
proteins
diameter of DNA
double helix
atoms

5. Cell types
Prokaryotic—no nucleus, circular DNA, ribosomes, peptiglycon-prokayotic cell wall
a. Carbohydrate matrix cross linked with peptide units
Eukaryotic—larger, nucleus, linear chromosomes, membraned organelles,
Compartmentalization
Include true bacteria
On earth 3.8 million years
Found nearly everywhere
Spores in each breath; intestines
Naturally in soil, air, hot springs

6. nucleoid (DNA) ribosomes food granule cytoplasm cell wall
prokaryotic
flagellum
Figure: 04-10
Title:
A generalized prokaryotic cell.
Caption:
plasma membrane
cytoplasm
cell wall

7. Eukaryotic Cells Have numerous internal structures
Various types & forms
Plants, animals, fungi, protists
Multicellular organisms Nucleus is control center of the cell
1. Membrane bound (nuclear envelope)
2. Contains nucleoli; synthesizes ribosomal RNA
3. DNA in chromosomes (DNA and proteins)

8. 1. Plant cells a. Square-geometric shaped b. Cell wall- cellulose
c. Chloroplast
d. No centrioles
e. Large vacuoles

9. (part of cytoskeleton)
microtubules
(part of cytoskeleton)
mitochondrion
chloroplast
Golgi complex
central vacuole
smooth endoplasmic
reticulum
vesicle
cell wall
rough endoplasmic
reticulum
plasma
membrane
Figure: 04-03
Title:
A generalized plant cell.
Caption:
nucleolus
nuclear pore
nucleus
chromatin
nuclear envelope
intermediate
filaments
ribosomes
free ribosome

10. Animal Cells
a. Irregular shaped
b. Just Cell membrane
c. Small vacuoles
d. Centrioles

11. nuclear pore chromatin (DNA) nucleus nucleolus nuclear envelope
flagellum
intermediate
filaments
cytoplasm
plasma
membrane
rough endoplasmic
reticulum
ribosome
lysosome
microtubules
Figure: 04-02
Title:
A generalized animal cell.
Caption:
smooth endoplasmic
reticulum
Golgi
complex
free ribosome
vesicle
mitochondrion
vesicle

12. nuclear envelope nucleolus nuclear pores chromatin Figure: 04-04a
Title:
The nucleus.
Caption:
(a) The nucleus is bounded by a nuclear envelope. Inside are chromatin (DNA and associated proteins) and a nucleolus.
chromatin

13. nucleus nuclear pores Figure: 04-04b Title: The nucleus. Caption:
(b) An electron micrograph of a yeast cell that was frozen and broken open to reveal its internal structures. The large nucleus, with nuclear pores penetrating its nuclear envelope, is clearly visible.

14. chromatin chromosome Figure: 04-05 Title: Chromosomes. Caption:
Chromosomes, seen here in a light micrograph of a dividing cell (on the right) in an onion root tip, are the same material (DNA and proteins) as the chromatin seen in nondividing cells adjacent to it, but in a more compact state.
chromosome

15. Figure: 04-06
Title:
Ribosomes.
Caption:
0.05 micrometers

16. Eukaryotic cell structure
Organelles
Endoplasmic reticulum consists of folded membranes attached to the nucleus
Rough ER is site of protein synthesis and protein secretion. Proteins made here are processed and shipped out of the cell

17. Eukaryotic Cell Structure
Ribosomes assemble amino acid into polypeptide chains
a. Associated with the ER
b. Composed of RNA and proteins
Proteins for inside the cell

18. rough endoplasmic reticulum
ribosomes
Figure: 04-07R-1
Title:
Rough endoplasmic reticulum.
Caption:
rough endoplasmic reticulum
0.5 micrometers

19. smooth endoplasmic reticulum
vesicles
Figure: 04-07R-2
Title:
Smooth endoplasmic reticulum.
Caption:
smooth endoplasmic reticulum
0.5 micrometers

20. Eukaryotic Cell Structure
Golgi apparatus are membranous sacs associated with ER
Processing and transport of proteins, lipids exported from the cell
Synthesis and transport of polysaccharides
Lysosomes are Golgi-derived vesicles containing digestive enzymes

21. ____________________________________________________________________________________________________________________________________________________________________________________________________

22. vesicles from ER vesicles leaving Golgi complex Golgi complex
Figure: 04-08
Title:
The Golgi complex.
Caption:
The Golgi complex is a stack of flat membranous sacs. Vesicles transport material from the ER to the Golgi (and vice versa) and from the Golgi to plasma membrane, lysosomes, and vesicles. Departing vesicles bud off from the Golgi on one face; arriving vesicles join it on the opposite face.

23. Energy sources for cell activities
Mitochondria provide energy for cellular functions (respiration)
a. Matrix/cristae
b. Have their own DNA and ribosomes; self- replicate
C. Bounded by double membrane-numerous
a. Outer membrane is smooth
b. Inner membrane is folded into contiguous layers called cristae
1. Cristae are stuffed with 100,000 enzymes
2. Site of cellular respiration-Oxidation
3. Divides into inner matrix and outer compartment
4. Associated with proteins of oxidative metabolism

25. 5 micrometers Figure: 04-E4-2d Title: An SEM photo. Caption:
(d) An SEM photo at much higher magnification, showing mitochondria, many of which are sliced open.
5 micrometers

26. Energy sources for cell activities
Chloroplasts—function in photosynthesis
1) Green—contain chlorophyll pigment
2) Stroma/grana (thylakoid stacks)
3) Have their own DNA and ribosomes; self-replicate
4) Up to 100 per cell
5) Become leucoplasts when deprived of light
a. Specialized amyloplasts store starch
b. Plastids are derived from proplastids

29. Cytoskeleton Cytoskeleton Surface structures Internal infrastructure
a. Actin filaments-microfiliments
a. Muscle movement
b. Pinches cell when it divides during cytokinesis
b. Microtubules
1. Hollow tubes of 13 protein protofilaments-made of tubulin
2. Function
a. Help move materials within the cell itself
b. Skeletal System
c. Aides in cell Division-spindle
d. Cilia, Flagella, sperm tails
c. Intermediate filaments
Surface structures
extensions of the plasma membrane
aid in movement of simple organisms

30. actin subunits subunit tubulin subunit Figure: 04-2 Title:
Cytoskeleton components.
Caption:
tubulin
subunit

33. Prokaryotes & Eukaryotes
Similarities & differences
Both surrounded by plasma membrane, but very different
Prokaryotes – Archaebacteria and Eubacteria
Eukaryotes – everything else

34. ____________________________________________________________________________________________________________________________________________________________________________________________________

35. Evolution of Eukaryotic cell
Endosymbiotic Hypothesis
Similarities between bacteria, mitochondria and chloroplasts
Self-reproducing by binary fission
Size of organism and genome
Single circular naked DNA
Proportion of (G & C) to (A & T)
Same sized ribosome
Protein synthesis inhibited by antibiotics
Enzymes for synthesis of DNA, RNA and protein
Electron transport system

36. ____________________________________________________________________________________________________________________________________________________________________________________________________

38. Plant & Animal Cells Similarities
Both constructed from eukaryotic cells
________________________________________________________________________________
Both contain similar organelles
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Both surrounded by cell membrane
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39. Plant & Animal Cells Differences Animals have Plants have
Cell wall – provides strength & rigidity
Have chloroplasts, photosynthetic
Animals have
Other organelle not found in plants (lysosomes formed from Golgi)
Centrioles, important in cell division

40. Brief Look at Viruses Viruses are acellular
Not considered to be living
Cause serious diseases in most organisms