Cell Organelles
Cell Theory
• Basic Unit of Life
• All organisms are made up of one or
more cells and the products of those
cells.
• All cells carry out life activities (require
energy, grow, have a limited size)
• New cells arise only from other living
cells by the process of cell division
3 Main Components (All Cells)
• Plasma Membrane/Cell Membrane
– Structure- a bi-lipid membraneouos layer
composed of proteins and carbohydrates (Fluid
like)
– Function- the cell membrane separates the cell
from its external environment, and is selectively
permeable.
• It protects the cell and provides stability
• Proteins are found embedded within the plasma
membrane, with some extending all the way through in
order to transport materials
• Carbohydrates are attached to proteins and lipids on
the outer lipid layer
Main Parts con’t
• Cytoplasm
– Structure – The jelly-like substance
composed of mainly water and found
between the cell membrane and nucleus.
The cytoplasm makes up most of the
“body” of a cell and is constantly
streaming
– Function – Organelles are found here and
substances like salts may be dissolved in
the cytoplasm.
Main Parts con’t
• Nucleus
– Structure – The largest organelle in the cell.
• Round and surrounded by a double membrane.
Has selectively permeable pores.
• Contains genetic information (DNA) on special
strands called chromosomes
– Function – The control center of the cell, for
cell metabolism and reproduction
Individual Organelles
• Endoplasmic Reticulum (E.R.)
– Network of canals filled with fluid
– “Transport system”, carry materials throughout
cell
– Some are Lined with Ribosomes others are not.
• Ribosomes
– Small particles found individually in the
cytoplasm and E.R.
– Produce proteins, “Factories” in the cell
Con’t
• Golgi Body/Apparatus
– Stacks of flattened membraneous materials
“Pancakes”
– Temporarily stores proteins until they leave cell
• Lysosomes
– Small sac-like structures surrounded by single
membrane
– Strong dygestive enzymes are released to break
down worn out organelles or food.
– “Suicide Sac”
Con’t
• Mitochondria
– Round “tube-like” organelles with double membrane
(Inner highly folded)
– “Powerhouse” of the cell releases food energy from
food molecules in cell.
– Called Respiration
– Muscle cells require more energy require more
mitochondria
• Vacuoles
– Fluid filled enclosed by membrane
– “Storage facility” of food, water, sugar, minerals, and
waste
Features of Plant Cells
• Cell Wall – Rigid organelle outside the membrane
composed of cellulose. Contains pores to allow
materials to pass to and from the cell membrane
• Central Vacuole – Large fluid filled vacuole
• Plastids – Double membrane organelles. Makes
and store food. Found in cytoplasm (2 types)
– Leucoplasts – colorless store startch and other
nutrients (potato startch)
– Chlorplast – Different colored pigment. Green
pigment chlorophyll important in photosynthesis