2. Cell components in animals VS
plants
– Animal Cell
– Cell Nucleus
– Cytoplasm “internal cell fluid”
– Cell membrane
– Vesicles or “temporary
vacuoles”
– Plant Cell
– Cell Nucleus
– Chloroplasts “are often green”
– Cellulose Cell wall
– Cell membrane
– Nucleus
– Large , permanent vacuoles
– Cytoplasm
All these components
are known as
organelles , they do
specific functions
within the cell
3. Cell organelles’ specific functions
I. Cell Wall: A fully permeable structure made up of cellulose. A cell wall
Supports the cell against outside pressure , maintaining the cell shape.
II. Cell membrane: a partially permeable membrane made of phospholipids &
proteins, it controls movement of organelles and molecules inside and outside of cells, this
membrane separates the cell of its surroundings.
4. III. Cytoplasm: A clear jelly medium consisting of 70% water. It hosts all the other cell organelles, dissolved
substances e.g. mineral salts & glucose ,and undissolved inclusions as starch. The cytoplasm is the main
site of metabolic reactions.
IV. Nucleus: It’s an enclosed organelle covered with a nuclear envelope that
contains all the genetic information of the organism. The nucleus controls how
the cell develops and grows .In addition, it controls the cell’s metabolic reactions and
the making of proteins & enzymes.
V. Vacuole “cell sap vacuole”: A membrane-bound cavity that contains sap. A vacuole can be large and
permanent in a plant cell, however they can be small and temporary in animal cells and are more known as
vesicles. The vacuole stores all wasteful and useful materials. They also support the cells by their turgidity.
VI. Ribosomes: Protein-forming organelles that are found either free in the cytoplasm or
attached on a rough endoplasmic reticulum.
VII.Mitochondria: A membrane bound organelle that is found in the cytoplasm. A
mitochondria is the main site of aerobic respiration which is a process that releases energy.
Mitochondria is the power house of the cell
VIII.Chloroplasts “Plants only”: Large organelles that contain Chlorophyll “green pigment ”. Chloroplasts
trap and absorb sunlight to converts its energy into chemical energy ATP.
Sap :fluid that
contains sugars
,salts, water and
wastes.
5. Important Notes to be considered
– Eukaryotic cells: cells which have a true nucleus
– Prokaryotic cells: cells which do not have a true nucleus
– Ribosomes , nuclear envelopes and mitochondria can only be seen under
an electron microscope while all other organelles can be seen by a regular
light microscope.
– All cells have mitochondria and RER except Prokaryotes
True nucleus means that cell’s DNA is surrounded by
a membrane
