Cells and their Structure

1
Unit 4

• Cells and their Structure

2
Levels of Organization
3
Diversity of Cellular Life
4
Cell Specialization when a group of cells work
together to perform a specific job
5
(No Transcript)
6
(No Transcript)
7
The Cell Theory

• All living things are composed of cells
• Basic units of structure and function in living
  things
• Cells are produced from existing cells

8
Categories of CellsType 1 Prokaryotes

• Unicellular one cell
• No Nucleus DNA free floating
• Example Bacteria
• Used in technique called Recombinant DNA

9
Shapes of Prokaryotes

• Cocci spherical (round)
• Bacillus (rod shaped)
• Spirilla helical (spiral)

10
These are prokaryote E. coli bacteria on the
head of a steel pin.
11
What the heck is Recombinant DNA?  A series of
procedures that are used to join together
(recombine) DNA segments. A recombinant DNA
molecule is constructed from segments of two or
more different DNA molecules. Under certain
conditions, a recombinant DNA molecule can enter
a cell and replicate there, either on its own or
after it has been integrated into a
chromosome. For example Insulin Bacterial
DNA Antifreeze from fish tomato DNA Growth
Hormone Bacterial DNA Human (other) Human DNA
12
Why Make Recombinant DNA? Recombinant DNA
Technology May Allow Us To Cure or treat
disease Genetically modify our foods to
increase flavor, yield, nutritional value or
shelf-life Better understand human genetics
Clone cells or organs
13
Why use Prokaryotes-Bacteria? Theyre
relatively simple organisms. They reproduce
very quickly and asexually (this means that the
daughter cells will contain the exact same DNA
as the parent cell). Its pretty easy to get
DNA back into the bacteria after youve changed
it.
14
Step to Recombinant DNA
15
Steps to Recombinant DNA

• Step 1
• Isolate (find) the human gene responsible for
  producing insulin and decide where you want to
  put it.
• In this case, we decide to put our human DNA into
  the plasmid of E. coli, a very common bacterium.

16
PLASMID

• A small, circular DNA molecule found in bacteria
  known as a plasmid.

17

• Step 2
• Get the bacterial (plasmid) DNA out of the E.
  coli. We do this by basically
• exploding them.
• Step 3
• Cut your human DNA and bacterial DNA with the
  same restriction enzyme

18
Restriction enzymes

• A restriction enzyme (RE) is a specialized
  protein that cuts DNA in a very specific place.
• Molecular scissors

19

• Step 4
• Mix the cut human DNA, which contains the insulin
  gene, with the cut bacterial DNA.
• Theyll stick together because they were cut with
  the same restriction enzyme.

20
Step 5 Get your new recombinant plasmid back
into the bacteria. This is easy because bacteria
will take in DNA thats floating around near
them. We call this transformation.
21
Voila!! Now your E. coli will use its new DNA to
make human insulin! Because they reproduce so
quickly, youll soon have thousands, millions, or
billions of human insulin making machines. By
filtering out the bacteria after theyve
made insulin, youve got clean human insulin that
can be packaged and given to diabetic patients.
22
Virus?
23
A virus is an infectious agent made up of nucleic
acid (DNA or RNA) wrapped in a protein coat
called a capsid.
Viruses have no nucleus, no organelles, no
cytoplasm or cell membraneNon-cellular
vs
24
Replication is how a virus spreads. A virus
CANNOT reproduce by itselfit must invade a host
cell and take over the cell activities,
eventually causing destruction of the cell and
killing it. (The virus enters a cell, makes
copies of itself and causes the cell to burst
releasing more viruses.)
DNA/RNA is copied.
DNA/RNA injected into cell.
Virus attaches to cell.
Step 3
Step 2
Step 1
Virus copies itself.
Cell bursts (lyses) and releases new viruses.
Step 4
Step 5
25
Viruses are parasitesan organism that depends
entirely upon another living organism (a host)
for its existence in such a way that it harms
that organism.
HIV Cell
A flea is a parasite to a dog and is harmful to
the dog.
(This is the reason why HIV is so incurable.)
26
(No Transcript)
27
Categories of Cells Type 2 Eukaryotes

• Unicellular or Multicellular
• Has a Nucleus
• Example Plant, Animal, fungi

28
How are Eukaryotes Different from Prokaryotes
Eukaryotes have a nucleus that contains DNA and
Prokaryotes do not
29
Types of Cells in the Human Body

30
Two Types of Eukaryotes Animal and Plant Cell
Lets take a good look at these eukaryotes!
31
Cell Structures in common
Cell Membrane Nucleus Ribosome
Endoplasmic Reticulum Vacuoles Mitochondria
32
Only Plant cell Structure

• choroplast

• Cell wall

33
Only Animal cell Structure

• Centriole-involved in cell division

34
Nucleus

• Controls most of cells processes
• Contains genetic information-DNA
• Chromosomes inside nucleus are the threadlike
  structures containing genetic information

35
Nucleolus

• Found inside nucleus
• Produces ribosomes

36
Nuclear Envelope (membrane)

• Surrounds genetic material

37
Ribosomes

• Makes proteins for cell
• Instructions come from the nucleus

38
Endoplasmic Reticulum

• Synthesizing, packaging and transporting of
  proteins
• Two types rough ER and smooth ER
• Network of membranes

39
Golgi Apparatus

• Packaging system
• Takes small molecules and makes larger ones then
  stores them

40
Vacuoles

• Storage areas for water, salt, proteins,
  carbohydrates
• Large structures in plants

41
Mitochondria

• Synthesis and release of energy
• Powerhouse of cell

42
Cell Membrane

• Regulates what enters and exits the cell
• Provides protection and support
• Semi-permeable allows small substances through
  and keeps larger substances out
• Made of lipids and proteins

43
Cell Membrane
44
Cell Wall (Plant Only)

• Provides support, protection and structure for
  plant cell

45
Chloroplast (Plant Only)

• Site of photosynthesis