cell biology, cytology
Post on 04-Apr-2018
228 Views
Preview:
TRANSCRIPT
-
7/31/2019 Cell Biology, Cytology
1/64
-
7/31/2019 Cell Biology, Cytology
2/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Cytology, the study of the structure and function of cells
Cell biology
The human body contains both somatic and sex cells
-
7/31/2019 Cell Biology, Cytology
3/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
THE CELL TYPES
Structural unit of living organism Two fundamentally different types
The prokaryotic cells --- only in bacteria
The eukaryotic cells
-
7/31/2019 Cell Biology, Cytology
4/64
Cell Function Cells are the building blocks of all plants andanimals Cells are produced by the division of preexisting cells
Cells are the smallest units that perform all vitalphysiological functions Each cell maintains homeostasis at the cellularlevel
Homeostasis at higher levels reflects combined,coordinated action of many cells
-
7/31/2019 Cell Biology, Cytology
5/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
CELLULAR FUNCTION
Movement Synthesis and secretion of enzymes Synthesis and secretion of mucous substances Synthesis and secretion of steroids Ion transport Intracellular digestion Metabolite absorption Transformation stimuli into nerve impulses
-
7/31/2019 Cell Biology, Cytology
6/64
Cell Motility
The movement of whole cells is made possible throughthe membrane pliability and the rearrangement of thecytoskeleton and internal components
-
7/31/2019 Cell Biology, Cytology
7/64
A Typical Cellfilaments)
2. Has organelles that perform specificfunctions in the cell (Mitochondria -
produces energy)3. Has certain active genes to give the cell a
specific function (heart cells, liver cells, brain cells, etc)
4. Has the information to perpetuate the whole organism as well as its specificfunction (Nucleus - DNA)
-
7/31/2019 Cell Biology, Cytology
8/64Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Is surrounded by extracellular fluid, which is the
interstitial fluid of the tissue
A typical cell
Has an outer boundary called the cell membraneor plasma membrane
-
7/31/2019 Cell Biology, Cytology
9/64Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
CELLULAR FLUID Human body ------60 % is fluid
Most of this fluid is inside the cells intracellular fluid extracellular fluid ---about one third
Consist of ions and nutrients The environment of the cells =internal
environment of the body = milieuinterieur
-
7/31/2019 Cell Biology, Cytology
10/64Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
EXTRA AND INTRACELLULAR FLUID
Extra cellular Intracellular >> Na+ >> K+ Cl- Mg++ HCO3- Phosphates Nutrients
-
7/31/2019 Cell Biology, Cytology
11/64Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
The Anatomy of a Representative Cell
Figure 3.2
-
7/31/2019 Cell Biology, Cytology
12/64Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
13/64Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
THE CELL COMPONENTS
PLASMA MEMBRANE CYTOPLASM
Organelles : ribosome , endoplasmicreticulum, Golgi apparatus, lysosome,cytoskeleton ---embedded in thematrix ( cytosol )inclusion: carbohydrates, lipids andpigments
NUCLEUSNuclear envelope, DNA,chromosomes, chromatin andnucleolus
-
7/31/2019 Cell Biology, Cytology
14/64Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Nonmembranous organelles are not enclosed by a membrane and always in touch with the cytosol
Organelles
Cytoskeleton, microvilli, centrioles, cilia,ribosomes, proteasomes
Membranous organelles are surrounded by lipidmembranes
Endoplasmic reticulum, Golgi apparatus,lysosomes, peroxisomes, mitochondria
-
7/31/2019 Cell Biology, Cytology
15/64
Different Types of Cell Movement (related tostructural components)Internal - movement of proteins, molecules,
organelles
External - movement of molecules into or out of the cellDetermined by cell membrane function and dynamics
Determined by cytoskeleton dynamics
-
7/31/2019 Cell Biology, Cytology
16/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
PLASMA MEMBRANE
The outermost component of the cell Separates the cytoplasm from its
extracellular environment Contains protein called integrins
-
7/31/2019 Cell Biology, Cytology
17/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Membrane Structure
Primarily made up of lipids
Protein and carbohydrates
1. Lipids are the most abundantMembrane called phospholipid bilayer
Outermost portions - hydrophilic
Innermost layers - hydrophobic
-
7/31/2019 Cell Biology, Cytology
18/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Physical isolation
Cell membrane functions include:
Regulation of exchange with the environment
Changes in ECF, pH, receptorrecognition
Structural support
-
7/31/2019 Cell Biology, Cytology
19/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
PLASMA MEMBRANE
FUNCTION Maintening the structural integrity of the cell Selective permeability Regulates the cell- cell interaction Recognition to antigen and foreign cells via
receptor Transducing extracellular signals into intra
cellular Acting as an interface between the cytoplasm
and the internal milieu
-
7/31/2019 Cell Biology, Cytology
20/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
PLASMA MEMBRANE COMPOSITION PLASMA MEMBRANE COMPOSITION
PHOSPHOLIPID BILAYER : 1. POLAR HEAD (HYDROPHILIC HEAD) 2. NONPOLAR FATTY ACYL (HYDROPHOBIC )
PROTEIN MEMBRANE : 1. INTEGRAL PROTEIN
2. PERIPHERAL PROTEIN GLYCOCALYX : 1. GLYCOPROTEIN 2. GLYCOLIPID
-
7/31/2019 Cell Biology, Cytology
21/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Protein component
Integral proteins / transmembrane proteins : Directly incorporated within the lipid bilayer Can be extracted by drastic methods
Peripheral proteins : Exhibit a looser association with membrane surfaces Can be easily extracted with salt solutions
-
7/31/2019 Cell Biology, Cytology
22/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
PROTEIN MEMBRANE INTEGRAL PROTEIN
EXSTRACELLULAR SURFACE RECEPTORS
CHANNEL PROTEIN CARRIER PROTEIN
PERIPHERAL PROTEIN CYTOPLASMA SURFACE
G- PROTEIN, ADENYL CYCLASE (AC),GUANYL CYCLASE (GC),
PHOSPHOLIPASE C (PLC)
-
7/31/2019 Cell Biology, Cytology
23/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
The cell membrane is a phospholipid bilayer with
proteins, lipids and carbohydrates.
The Cell Membrane
Figure 3.3
-
7/31/2019 Cell Biology, Cytology
24/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
25/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
26/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
27/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
28/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
P bilit
-
7/31/2019 Cell Biology, Cytology
29/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
The ease with which substances can cross the cell membrane
Permeability
Nothing passes through an impermeable barrier Anything can pass through a freely permeable barrier
Cell membranes are selectively permeable
Selective permeability is based on size, electrical charges, molecularshape, and lipid solubility.
Transport of substances across the membrane can be Passive or ActiveActive transport requires energy to occur
Passive transport does not require energy
Diffusion, Osmosis and Active Transport are different types of movement
-
7/31/2019 Cell Biology, Cytology
30/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
TRANSPORTATION VIA MEMBRANE
Passive without energy
Simple diffusion Fasilitated diffusion
Active with energy
-
7/31/2019 Cell Biology, Cytology
31/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
MEMBRANE TRANSPORT PROTEINS
Channel Proteins:
Participate in formation of hydrophilic pores ion channels,across the plasmalemma
Gated or ungated Incapable of transporting substances against concentration
gradient
Carrier proteins : Can mediate such energy requiring active transport Multipass membrane transport proteins Possess binding sites for specific ions or molecules on
both sides Transport by carrier proteins can be passive or active Can be uniport or coupled ( symport and antiport )
-
7/31/2019 Cell Biology, Cytology
32/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Fi 3 19 Diff i h C ll M b
-
7/31/2019 Cell Biology, Cytology
33/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 3.19 Diffusion across the Cell Membrane
Figure 3.19
-
7/31/2019 Cell Biology, Cytology
34/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
35/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
36/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
37/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
38/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
39/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
-
7/31/2019 Cell Biology, Cytology
40/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Cytoskeleton provides strength flexibility and
-
7/31/2019 Cell Biology, Cytology
41/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Microfilaments(6nm) -
1. anchor cytockeleton to integral proteins,2. determine the consistency of the cytoplasm,3. interacts with myosin to produce movement
Cytoskeleton provides strength, flexibility andmotility
Intermediate filaments ( 7-11 nm)- Protein composition varies between cell types.1. Strengthen cell and help maintain shape;
2. Stabilize the position of organelles
3. Stabilize the position of the cell with respect to surrounding cells thru
specialized membrane attachments
-
7/31/2019 Cell Biology, Cytology
42/64
Microtubules (up to 25nm)all cells contain microtubules, made up of protein tubulin. Largest cytoskeletal component
Functions:
1. Primary cytoskeletal component
2. Disassembly of microtubules provides a mechanism forchanging the shape of the cell and assisting in movement
3. Used to transport other proteins around the cell in associationwith motor proteins kinesin and dynein
4. Forms spindle apparatus during cell division
5. Form structural cell components such as cilia and centrioles
Figure 3 5 The Cytoskeleton
-
7/31/2019 Cell Biology, Cytology
43/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 3.5 The Cytoskeleton
Figure 3.5
Figure 3 8 The Endoplasmic Reticulum
-
7/31/2019 Cell Biology, Cytology
44/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 3.8 The Endoplasmic Reticulum
Figure 3.8
Site of protein and lipid synthesis
Figure 3 9 The Golgi Apparatus
-
7/31/2019 Cell Biology, Cytology
45/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 3.9 The Golgi Apparatus
Figure 3.9
Forms secretory vesicles
Forms new membrane components
Figure 3 10 Functions of the Golgi Apparatus
-
7/31/2019 Cell Biology, Cytology
46/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 3.10 Functions of the Golgi Apparatus
Figure 3.10
Lysosomes and Peroxisomes
-
7/31/2019 Cell Biology, Cytology
47/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Lysosomes are
Lysosomes and Peroxisomes
Filled with digestive enzymes
Responsible for autolysis of injured cells
Peroxisomes
Carry enzymes that neutralize toxins
Figure 3 11 Lysosome Functions
-
7/31/2019 Cell Biology, Cytology
48/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 3.11 Lysosome Functions
Figure 3.11
Mitochondria
-
7/31/2019 Cell Biology, Cytology
49/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Responsible for ATP production through aerobicrespiration
Mitochondria
Matrix = fluid contents of mitochondria
Cristae = folds in inner membrane
The nucleus is the center of cellular operations
-
7/31/2019 Cell Biology, Cytology
50/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Surrounded by a nuclear envelope
The nucleus is the center of cellular operations
Perinuclear space
Communicates with cytoplasm throughnuclear pores
Figure 3 13 The Nucleus
-
7/31/2019 Cell Biology, Cytology
51/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 3.13 The Nucleus
Figure 3.13
Contents of the nucleus
-
7/31/2019 Cell Biology, Cytology
52/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
A supportive nuclear matrix
Contents of the nucleus
One or more nucleoli
Chromosomes
DNA bound to histones
Chromatin
Figure 3 14 Chromosome Structure
-
7/31/2019 Cell Biology, Cytology
53/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 3.14 Chromosome Structure
Figure 3.14
The genetic code
-
7/31/2019 Cell Biology, Cytology
54/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
The cells information storage system
The genetic code
Triplet code
A gene contains all the triplets needed to codefor a specific polypeptide
Gene activation and protein synthesis
-
7/31/2019 Cell Biology, Cytology
55/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Gene activation initiates with RNA polymerase binding to the gene
Gene activation and protein synthesis
Transcription is the formation of mRNA fromDNA
mRNA carries instructions from the nucleusto the cytoplasm
-
7/31/2019 Cell Biology, Cytology
56/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
SECTION 3-6 The Cell Life Cycle
cell division
-
7/31/2019 Cell Biology, Cytology
57/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Cell division is the reproduction of cells
cell division
Apoptosis is the genetically controlled death of cells Mitosis is the nuclear division of somatic cells Meiosis produces sex cells
Interphase
-
7/31/2019 Cell Biology, Cytology
58/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Most somatic cells spend the majority of theirlives in this phase
Interphase
Interphase includes
G1 S
G2
Figure 3.27 The Cell Life Cycle
-
7/31/2019 Cell Biology, Cytology
59/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 3.27 The Cell Life Cycle
Figure 3.27
Figure 3.28 DNA Replication
-
7/31/2019 Cell Biology, Cytology
60/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
g p
Figure 3.28
Mitosis, or nuclear division, has four phases
-
7/31/2019 Cell Biology, Cytology
61/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Prophase
, , p
During cytokinesis, the cytoplasm divides andcell division ends
Metaphase
Anaphase
Telophase
Figure 3.29 Interphase, Mitosis, and Cytokinesis
-
7/31/2019 Cell Biology, Cytology
62/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
g p , , y
Figure 3.29a-d
Figure 3.29 Interphase, Mitosis, and Cytokinesis
-
7/31/2019 Cell Biology, Cytology
63/64
Copyright 2004 Pearson Education, Inc., publishing as Benjamin Cummings
g p , , y
Figure 3.29e, f
Differentiation
-
7/31/2019 Cell Biology, Cytology
64/64
Process of specialization
Results from inactivation of particular genes
Produces populations of cells with limitedcapabilities
Differentiated cells form tissues
top related