Download Chp 2 Cell structure

What is cell?
Cell is the basic unit that build up
organism.
What do you call the structures in a cell?
The structures in a cell is called organelles.
State the organelles in an animal cells.
Cell membrane, mitochondrion, rough
endoplasmic reticulum, smooth endoplasmic
reticulum, ribosome, centriole, golgi
apparatus.
Animal Cell
1
2
3
4
5
6
7
8
Plant Cell
ch
cw
Plant Cell
Chloroplast
Cytoplasm
Nucleus
Vacuole
Cell membrane
Cell wall (made of
cellulose)
Nucleus
Endoplasmic Reticulum
Ribosome
Golgi Apparatus
Plasma membrane
Mitochondrion
Lysosome
Centrioles
Chloroplast
Cell Wall
Activity 2.1.2
Draw a table to list the functions of organelles in animal cells
and plant cells.
Organelles
Functions
Task 2.1.2 Complete the below table to state the
functions of each organelle.
Organelle
Functions
Cell
membrane
Cell membrane forms a boundary to separate the content
of a cell from outer environment.
Cell membrane regulates the movement of substances
into and out of the cytoplasm.
Cell wall
Cell wall gives shape to a plant cell.
Cell wall provides mechanical support for the plant cells.
Cytoplasm
Cytoplasm acts as a medium for biochemical reactions in
the cell.
Nucleus
Nucleus contains genetic information that determines the
characteristics and functions of the cell.
Nucleus controls all the activities which take place in the
cell.
vacuole
Vacuole regulates water balance in the cell.
Vacuole acts as a storage place in a cell.
Mitochondrion
Mitochondria carry out cellular respiration to release
energy in form of ATP.
Ribosome
Ribosomes synthesise protein.
Endoplasmic
reticulum
Rough ER transports proteins made by ribosome.
Smooth ER is the site of metabolic reactions – synthesis of
lipids and detoxification of drugs and poisons.
Golgi apparatus Golgi apparatus process, package and transport
carbohydrates, proteins, phospholipid and
glycoprotein.
Lysosome
Lysosome contains hydrolytic enzymes to digest
complex organic molecules.
Lysosome eliminates worn out mitochondria and other
damaged organelles.
Centriole
Centriole functions during cell division in animal cells.
Chloroplasts
Chloroplast traps sunlight and converts light energy
into chemical energy during photosynthesis
You have learnt about the cellular components of animal and plant
cells. Now, carry out a discussion among your group to compare and
contrast the structure of animal and plant cells. You can present your
findings by using table.
Animal Cell
Plant Cell
Animal Cell
CORRECTIONS
Plant Cell
Animal cell does not have fixed
Plant cell has fixed/regular shape.
Similarities:
shape / regular shape.
Both animal cell and plant
cell have a
Animal cell does not have cell
Plant cell has cell wall.
nucleus, a plasma membrane, cytoplasm,
wall.
Golgi
rough
Animal
cellapparatus,
does not have mitochondria,
All green plants
have
chloroplasts.
endoplasmic reticulum,chloroplasts.
smooth endoplasmic
Animal
cell does not
have
Mature plant cell has a large
reticulum
and
ribosomes.
vacuole or if have, vacuoles are central vacuole.
usually small and numerous.
Differences:
Animal cell has centrioles.
Plant cell does not have
centrioles.
Animal cell stores carbohydrate in Plant cell stores carbohydrate in
the form of glycogen.
the form of starch.
How does a unicellular organism perform its living processes?
•It depends on its cellular components
which include the organelles.
The density of organelles in specific cells
Multicellular organisms are made up of many
types of cells.
The cells undergo specialisation to become specific in order
to perform different function. Therefore, certain organelles are found
abundantly in the specific cells.
For example, pancreatic cells which synthesise and secrete enzymes
and hormones contain a high density of rough endoplasmic reticulum.
Cells
Tissues
Organism
Organs
Systems
Example of cell organisation in digestive system in a human
Cell organisation
Cell organisation in mammals
Cells
Tissues
Organs
Systems
Permanent
tissues
Meristematic
tissues
are
Young, actively
Dividing cells
haven’t
have
Differention
are
have
consist of
Tips of roots
and buds of
shoots
Mature
tissues
Differention
located at
thin walls,
large nuclei,
dense
cytoplasm,
no vacuoles.
Organism
epidermal tissues,
ground tissues,
vascular tissues.
Different types of cells in plants which have been
undergone specialisation
Plant cell types in tissues – Ground tissues
Parenchyma
• “typical” plant cells = least
specialized
• photosynthetic cells, storage
cells
• tissue of leaves, stem, fruit,
storage roots
Collenchyma
• unevenly thickened primary
walls = support
Sclerenchyma
•very thick, “woody”
secondary walls = support
•rigid cells that can’t elongate
• dead at functional maturity
Vascular tissue
•Transports materials in roots, stems
& leaves
Xylem
•-carry water & minerals up
from roots
•tube-shaped dead cells
•only their walls provide a system
of microscopic water pipes
Phloem
•carry nutrients throughout plant
•sugars (sucrose), amino acids…
• tube-shaped living cells
Regulating the internal environment
Cells bathe in the internal environment which contain
interstitial fluid.
The internal environment must be regulated to maintain
its level. Do you know why?
The constant internal environment ensure the cells to
function optimally.
The process involves in maintaining the balance of
homeostasis
internal environment is called ………………………….
Which type of mechanisms involves in homeostatic
mechanism?
The value
rises above
the set point
Normal
value
(set point)
Corrective
mechanism
Normal
value
(set point)
The value
drops below
the set point
Corrective
mechanism
Vacuole
Sample Answer : Compare and contrast animal cell and plant cell
Animal Cell
Plant Cell
•Both animal cell and plant cell have plasma membrane, nucleus,
cytoplasm, ribosomes, endoplasmic reticulum, Golgi apparatus and
mitochondrion.
•Animal cell has centriole and
•Plant cell does not have centriole
lysosome.
and lysosome.
•Animal cell does not have cell
wall, large central vacuole, and
chloroplast.
•Animal cell has irregular shape.
•Animal cell stores carbohydrates
in the form of glycogen.
•Plant cell has cell, wall, large
central vacuole, and chloroplast.
•Plant cell has regular / fixed
shape.
•Plant cell stores carbohydrates in
the form of starch.
Sample Answer: By giving appropriate examples, describe how different organelles
work together to enable the cell to function in an orderly manner.
Pancreas cell functions to produce enzyme. To
produce enzyme, ribosome sends mRNA messenger
to nucleus to copy DNA code. mRNA messenger
returns to ribosome. Ribosome synthesise proteins
based on the code. Proteins enters rough
endoplasmic reticulum and is enclosed in vesicle.
Vesicle with proteins fuses with Golgi apparatus. The
proteins is modified to form specific enzyme. Then,
the enzyme is enclosed in secretory vesicle. The
secretory vesicle will fuse with plasma membrane and
releases the enzyme out from the cell.