Download presentation
Presentation is loading. Please wait.
1
Cells
2
The 3 Basic Parts of all Cells
Plasma Membrane Controls what enters & exits the cell Cytoplasm Entire contents of cell between P.M. and nucleus Where most metabolic activity occurs Nucleus or Nuclear Area Contains DNA, the genetic material
3
Phospholipids form a two-layer sheet
Called a phospholipid bilayer, with the heads facing outward and the tails facing inward Water Hydrophilic heads Hydrophobic tails Figure 5.11B
5
Classes of Cells Two basic types of cells: Prokaryotic cells
Eukaryotic cells
6
Prokaryotic cells are structurally simpler than eukar yotic cells
Nucleoid region Nucleus Eukaryotic cell Organelles Colorized TEM 15,000 Figure 4.3A
7
Prokaryotic Cell Pili Cell wall Plasma membrane Nuclear area Ribosomes
Figure 4.3B Pili Cell wall Plasma membrane Nuclear area Ribosomes Flagella
8
Eukaryotic cells Animal Cell Fig 4.4A
9
1. The nucleus is the cellular control center
Containing the cell’s DNA, which directs cellular activities Nucleus Chromatin Two membranes of nuclear envelope Nucleolus Pore Rough endoplasmic reticulum Figure 4.5 Ribosomes
10
2. Smooth endoplasmic reticulum, or smooth ER Synthesizes lipids
Processes toxins and drugs in liver cells Stores and releases calcium ions in muscle cells Smooth ER Rough ER Nuclear envelope Ribosomes Smooth ER Rough ER TEM 45,000 Figure 4.7
11
3. Rough endoplasmic reticulum or Rough ER Ribosomes on the surface
Produce proteins that are secreted, inserted into membranes, or transported in vesicles to other organelles Transport vesicle buds off Secretory (glyco-) protein inside trans- port vesicle 4 Polypeptide Ribosome 1 3 Sugar chain Figure 4.8 Rough ER Glycoprotein 2
12
4. The Golgi apparatus finishes, sorts, and ships cell products
Stacks of membranous sacs receive and modify ER products then ship them to other organelles or the cell surface Figure 4.9 Golgi apparatus “Receiving” side of Golgi apparatus Golgi apparatus Transport vesicle from ER TEM 130,000 New vesicle forming Transport vesicle from the Golgi “Shipping” side of Golgi apparatus
13
5. Vesicles: Membrane-bound “balloons” that transport and store substances in cells
14
6. Lysosomes are sacs of enzymes
function in digestion within a cell Lysosomes in white blood cells destroy bacteria that have been ingested recycle damaged organelles
15
Fig 4.13 The various organelles of the endo-membrane system are inter-connected structurally and functionally
16
7. Mitochondria harvest chemical energy from food
Mitochondria carry out cellular respiration which uses the chemical energy in food to make ATP for cellular work Mitochondrion Outer membrane Intermembrane space Figure 4.14 Inner membrane TEM 44,880 Cristae Matrix
17
8. Cytoskeleton & related structures - a network of protein fibers
help organize its structure and activities Fig 4.17 Tubulin subunit Actin subunit Fibrous subunits 25 nm 7 nm 10 nm Microfilament Intermediate filament Microtubule
18
Microfilaments of actin Intermediate filaments
Enable cells to change shape and move Intermediate filaments Reinforce the cell and anchor certain organelles Microtubules give the cell rigidity And provide anchors for organelles and act as tracks for organelle movement
19
Cilia and flagella move when microtubules bend
Eukaryotic cilia and flagella are locomotor appendages that protrude from cer tain cells LM 600 Colorized SEM 4,100 Figure 4.18
20
Tight junctions Anchoring junctions Gap junctions
can bind cells together into leakproof sheets Anchoring junctions link animal cells into strong tissues Gap junctions allow substances to flow from cell to cell Tight junctions Figure 4.18B Anchoring junction Gap junctions Extracellular matrix Space between cells Plasma membranes of adjacent cells
22
Please do the activities at the following 2 sites:
23
Plant Cell –Fig. 4.6b
24
Plant cells also have: Vacuole stores water, solutes, waste
Important for growth and rigidity Chloroplasts Site of photosynthesis: conversion of light to ATP which drives formation of sugars Cell wall Protects, supports **Plant cells do not have lysosomes
25
Vacuoles function in the general maintenance of the cell
lysosomal and storage functions Chloroplast Central vacuole Nucleus Colorized TEM 8,700 Figure 4.12
26
Chloroplasts convert solar energy to chemical energy
found in plants and some protists convert solar energy to chemical energy in sugars TEM 9,750 Chloroplast Stroma Intermembrane space Inner and outer membranes Granum Figure 4.15
27
have rigid cell walls made of cellulose
Plant cells have rigid cell walls made of cellulose Are connected by plasmodesmata - connecting channels Plasma membrane Cytoplasm Plasmodesmata Vacuole Layers of one plant cell wall Walls of two adjacent plant cells Figure 4.22
Similar presentations
