cell structure and cell organisation · 2/1/2018 · cell structure and cell organisation chapter...
TRANSCRIPT
Nucleolus
Nucleus
Ribosomes
Vesicles
Golgi
Apparatus
Rough Endoplasmic
Reticulum
Plasma
membrane
Smooth Endoplasmic
Reticulum
Mitochondrion
LysosomeVacuole
Centriole
Cytoplasm
Cellular components
Organelles
Vacuoles
Nucleus
Ribosomes
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Centrioles (animal cell only)
Chloroplast (plant cell only)
Non-organelles
Plasma membrane
Cytoplasm
Cell wall (plant cells only)
https://wickedbiology.wordpress.com
Nucleolus
Nucleus
Controls all the cell activities
Separates the genetic material
from cytoplasm
Has many pores (nuclear pores) in
the nuclear membrane for
materials to enter & exit the nucleus
Nucleolus is involved in the synthesis
of ribosome & ribonucleic acid (RNA)
Ribosomes
Are either attached to the ER
or occur freely in the
cytoplasm
Are small ‘protein factories’
for protein synthesize
Synthesizes &
transports proteins
made by ribosomes
Present in large
amounts in cell that
makes protein
E.g. in gut cells that
manufacture
digestive enzymes
Rough Endoplasmic
Reticulum
Receives proteins
from Rough ER,
modifies & combines
the proteins with
carbohydrates to
form glyco-protein
Transport & stores
lipids
Golgi Appratus
Does not have
ribosomes
Synthesizes &
transport lipids
Present in large
amounts in cells that
make lipids & steroids
E.g. cell of liver &
testes
Smooth Endoplasmic Reticulum
Forms the cell’s
powerhouse
Produce adenosine
triphosphate (ATP),
which is the energy
source for the cell
Mitochondrion
Supports & protects
the cell organelles
provides a medium
for all cellular
metabolic reactions
Cytoplasm
medium to produce
energy, to manufacture
materials & to store
minerals
Break down macromolecules such as
proteins, lipids, nucleic acids, polysaccharides
as well as worn-out organelles
Lysosome
Transport undigested
material to the cell
membrane for
removal
The outer covering of
the cell
separates the cell
from its environment
and allows materials
to enter and leave
the cell
Plasma membrane
https://wickedbiology.wordpress.com
Animal cells Plant cell
Similarities
Both animal and plant cells have plasma membrane, cytoplasm, nucleus,
endoplasmic reticulum, Golgi apparatus, ribosomes and mitochondria
Differences
Not fixed SHAPE Fixed
Absent CELL WALL Present
Absent CHLOROPLAST Present
If present, are small & scattered throughout the cell
VACUOLE Has one or a few large vacuole(s) filled with cell sap
Present LYSOSOME Normally absent
Present CENTRIOLE Absent
Carbohydrates are stored in the form of glycogen granules
FOOD STRORAGE Carbohydrates are stored in the form of starch grains
What are organelles?
“little organs”
Are tiny structures inside a cell that
perform specific functions for the
cell
20
What are organelles?
“3 main functions of organelles:
a. Carry out their specialized functions:
E.g. Mitochondria; FUNCTION?
b. Acts as containers to separate parts of the cell from other
parts
E.g. lysosomes
c. Sites for chemical reaction
E.g. Chloroplast
Relationship between the Density &
Functions of certain Organelles
Density of an organelles :
total number of that particular organelles within
a cell
depends on the function of the cell
to make sure that the cell can perform its specialized functions well
Relationship between the Density
& Functions of certain Organelles
E.g.
Cell that specialize in producing enzyme generally have more ER &
ribosomes to _____________& mitochondria to
_____________________for its activities
The density of mitochondria in
active cells
Depends on:
a) The activity level of an organism
The more active an organism is, the higher its average density of mitochondria
b) The specific function of a particular cell
Cell of active tissues & organs have higher mitochondria densities
The density of mitochondria in
active cells
Active cells that have high mitochondria densities:
Sperm cells
flight muscle cells
meristemic cells
liver cells
kidney cells
The density of Chloroplast in the
Palisade Mesophyll Cells of
Leaves
Palisade mesophyll
of a leaf is : the main photosynthesis
tissue
Packed with chloroplast
to trap sunlight needed to
synthesize sugar during
photosynthesis
Are arranged in a vertical
position to optimise
sunlight trapping
Type of cells Function Density of certain
organelles
Sperm cells To swim towards either one of the Fallopian tubes to fertilise the ovum
Mitochondria – are sites of cellular respiration in which energy in the form of ATP is generated through oxidation of food substances such as glucose
Flight muscle cells
insects and birds
Contraction and relaxation of muscles
provide movement & locomotion
Mitochondria
Cells in the meristem Divided actively to produce new cells for growth
Mitochondria
Palisade mesophyll cells
Carry out photosynthesis Chloroplast – contain chlorophyll which trap light energy for photosynthesis
Goblet cells in the respiratory tract
Secrete mucus Golgi apparatus
Liver cells Detoxification of drugs Smooth endoplasmic reticulum
Pancreatic cells, cells of salivary glands, stomach cells, cells of intestine
Produce enzyme Rough endoplasmic reticulumand golgi apparatus