1. Girls Records
5/24/2019
Chapter 3
The Cell

2. Cell Structure Review
Cell Membrane
property/gate
September

3. Cell Membrane Review Composition Proteins Carbohydrates Lipids
September

4. Structure of Cytoplasm
definition: the material btw the plasma membrane and the nuclear membrane
September

5. Cytosol gel-like; fluid portion of the cytoplasm, intracellular fluid
September

6. Cytosol Contents
higher potassium, lower sodium concentrations (the opposite is found in extracellular fluid!), more dissolved proteins, less carbohydrates, some amino acids and lipids
September

7. Cytosol Contents insoluble material: inclusions
include nutrients and lipid droplets
September

8. Organelles: Cytoplasm Contents “little organs”
intracellular structure that performs a specific function or group of functions
September

9. Cytoskeleton
definition: a protein framework of microtubules & microfilaments
functions: strength and flexibility
September

10. Microfilaments thinnest composed of protein actin
attach plasma membrane to underlying cytoplasm
September

11. Intermediate Filaments
intermediate in size
protein composition varies
function for strength and stability
some specialized like keratin fibers in superficial layers of skin for strength
September

12. Microtubules microscopic hollow tubules of globular protein tubulin
function for strength and rigidity
found in cilia, flagella, centrioles, and spindle fibers
September

13. Microvilli
small finger-like extensions of the exposed plasma membrane of an epithelial cell
function to increase surface area for absorption
September

14. Centrioles [aka centrosomes]
cylindrical
composed of 9 groups of
microtubules (3 in each group)
functions in mitosis/meiosis
by organizing the microtubules
of the spindle apparatus
some cells lack these,
hence no dividing
September

15. Cilium (cilia p) slender extending above free surface
anchored by basal bodies
undergoes cycles of mvmt.
composed of microtubules
September

16. Flagellum [ flagella p ]
structurally similar to cilium
used to propel cell through fluid
only human example: sperm
September

17. (g) Ribosomes contains rRNA & proteins protein-making machines !!
free : scattered
fixed : attached
September

18. Proteosomes aka proteases
hollow, cylindrical
protein breaking enzymes
function in removal and recycling damaged or denatured proteins and breaking down abnormal proteins such as those produced w/ in cells infected by viruses
September

19. Endoplasmic Reticulum
channels
intracellular
transportation
SER:free ribosomes
RER: fixed
ribosomes ER
the grand canal
Rough
Smooth
September

20. Golgi body (flattened sacs) modification & packaging “recycling plant”
Girls Records
5/24/2019
Golgi body
(flattened sacs)
modification & packaging
“recycling plant”
Aka: golgi apparatus
September

21. Lysosomes known as cellular suicide package
lysosomal membranes disintegrate releasing enzymes
autolysis
September

22. Peroxisomes smaller carry different enzymes generate H2O2 in process
free radical: ion or molecules containing unpaired e-
may enter into destructive reactions
September

23. Mitochondria [aka mitochondrion s ]
generates ATP = energy
# varies depending on energy needs of cell
reaction sequence is glycolysis
if O2  aerobic metabolism or cellular respiration
produces about 95% of cell’s energy needs
September

24. Mitochondrion
September

25. Any Questions ??
September

26. The Structure of the Nucleus
Coming Next:
The Structure of the Nucleus
September

27. Cell Structure Review
September

28. Cell Structure Review
September

29. Structure of Nucleus contains DNA, RNA, and proteins
functions as control center for cellular activity
September

30. Structure of Nucleus cont’
Nucleolus: dense region in nucleus that represents the site of rRNA (ribosomal) synthesis
Nuclear envelope: double membrane surrounding the nucleus
Nucleoplasm: fluid contents
Nuclear pores: permit mvmt. Of material btw nucleus and cytosol
September

31. September

32. Chromosomes dense structures composed of tightly coiled DNA strands
associated w/ histones (special protein that guards the activity of each gene)
become visible in the nucleus when a cell prepares to undergo mitosis /meiosis
Human somatic cells contain 46
September

33. September

34. Chromatin
loosely coiled tangle of fine filaments in a cell not dividing that condenses in a dividing cell
September

35. Information Storage Genetic code:
chemical language (sequencing of amino acids) of cell to construct proteins
single DNA molecule: pair of DNA strands, H bonds btw complementary
N-bases
info in sequence of bases (A,T,C,G) in triplet code for amino acid
Ex: ACA = cysteine
September

36. Information Storage cont’
Gene: functional unit of heredity
has all triplets needed to produce specific proteins, or tRNA or rRNA
promoter or control
segment: special region of
DNA for regulating gene
activity
September

37. Protein Synthesis Where are the ribosomes? genes?
Transcription: the encoding of genetic instructions on a strand of mRNA
mRNA = messenger RNA is a transcript (copy) of info in the gene
September

38. Protein Synthesis cont’
RNA polymerase binds to promoter of gene synthesizing mRNA strand
RNA bases: A,C,G, and uracil (U)
codon: sequence of 3-Nbases along an mRNA strand that will specify the location of a single amino acid in a peptide chain
September

39. Protein Synthesis cont’
Translation: the process of peptide formation using the information from mRNA
begins when synthesized mRNA leaves nucleus and binds w/ a ribosome in cytoplasm
tRNA = transfer RNA delivers amino acids to be used by ribosome to assemble protein
September

40. Protein Synthesis cont’
more than 20 types of tRNA
anticodon: triplet of N-bases on a tRNA molecule that interacts w/ an appropriate codon on a strand of mRNA
takes about 20 seconds to produce a typical protein!
September

41. September