The Cell Theory 1 All life forms are made from one or more cells 2 Cells only arise from preexisting cells 3 The cell is the smallest form of life Types of Cells Prokaryotic ID: 429993
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Slide1
The Function of the Nucleus within the CellSlide2
The Cell Theory:
1. All life forms are made from one or more cells.
2.
Cells only arise from pre-existing cells.
3.
The cell is the smallest form of life.
Types of Cells:
Prokaryotic
– smaller, simple cells – no membrane-bound nucleus
(bacteria and blue-green algae)
Eukaryotic
– larger, more complex cells – have nucleus and other organelles
o
(protozoa, algae, slime molds, kelp)
o
(mushrooms, yeast, and lichen)
o
(plants)
o
(animals)
All eukaryotic cells have three parts in common:
Cell Membrane Nucleus Cytoplasm Slide3Slide4
Animal CellSlide5
Plant CellSlide6
Cell Membrane
Function:
control what enters/leaves the cell
Cytoplasm
Function:
suspend and support the organelles provide water for the cell’s chemical reactions
Mitochondria
Function:
provide energy for cell (respiration)
Chloroplast
Function:
make own food (photosynthesis)
Ribosomes
Function: make proteins
Endoplasmic Reticulum (ER)
Function: transport proteins
Golgi body
Function: process and package the proteins
Vacuoles
Function:
storage sacs (waste, water , nutrients (e.g. water/starch))
Cell Wall
Function:
protect & supportSlide7Slide8
The Nucleus – Control
center
of the Cell
The
nucleus contains the master set of instructions that determines what each cell will become, how it will function, when it will grow and divide, and when it will die.
Nucleolus – function: makes ribosomes
Nuclear Pore –allows only certain materials in/outSlide9
The Nucleus – Control centre of the Cell
Inside the nucleus are special structures called
chromosomes
.
When
a cell is at rest (not dividing), the DNA is relaxed and uncoiled forming a structure called
chromatin
.
When
the cell is ready to duplicate, the DNA condenses and coils up again forming chromosomes.
Therefore
, chromatin and chromosomes are the same thing (DNA and protein), but one is coiled and the other is uncoiled. Slide10
The Nucleus – Control centre of the Cell
Most
human cells have 46 chromosomes arranged in 23 pairs, including one pair of chromosomes that help determine sex.
In
males, the 23
rd
pair of chromosomes is the XY pair.
In
females, it is the XX pair. Slide11
The Nucleus – Control centre of the Cell
The DNA (
deoxyribonucleic acid
) molecules that make up chromosomes look like a twisted ladder
called a
double
helix.
Each half of the helix (
nucelotides
) are made up of phosphate, sugar and a base group.
The
steps of the ladder are made up
with
4 nitrogen bases…
A
(Adenine)
G (Guanine) C (Cytosine)
T
(Thymine)Slide12
The Nucleus – Control centre of the Cell
Everything that occurs within a cell is the result of how the bases on the DNA molecule
are arranged. This arrangement is known as the
DNA message
.
Base Pairs
in the DNA molecule always join in a specific way…
A joins with T
G joins with C
In
humans, a single DNA molecule can be several million base pairs in length.Slide13
Finish the DNA message
G A T T A C G G G G T T A A C C
C T A
A
T G C
C
C
C A A T
T G GA joins with TG joins with C
Slide14
The Nucleus – Control centre of the Cell
Genes
are the blue prints (small segment of DNA) to produce 90 000 to 100 000 different proteins used in the cells of your body.
- located
at specific places on a chromosome.
Every
chromosome carries thousands of genes and therefore contains the information to make thousands of different proteins.Slide15
The Nucleus – Control centre of the Cell
Proteins
determine what body cells will become and how they will function
When cells make one type of protein they become specialized to carry out a particular function Slide16
The Nucleus – Control
centre
of the CellSlide17
Protein production
The nucleus receives a chemical signal to make a specific protein.The DNA message for the protein is copied into a small molecule called RNA (Ribonucleic acid).RNA leaves the nucleus through a nuclear pore.
The RNA message is delivered to a ribosome, the ribosome makes the protein.
The manufactured protein enters the endoplasmic reticulum (ER) and a
vesicle forms at the end of the ER, and carries the protein to the Golgi body.
The Golgi body repackages the protein for transport out of the
cell
and a vesicle forms off the end of the Golgi body to carry the protein to the cell membrane.