Download File

Cell Organelles
CELL PARTS II
Lysosomes
 Membrane bound organelles that contain these
hydrolytic enzymes to break down materials
(proteins, fats, polysaccharides, etc…).
 If a lot of lysosomes burst (“suicide sac”), the cell
dies. Ex: Tadpole tails, and tissues between fingers
of human embryos
Food digested with primary lysosomes
Mitochondria:
Used to phosphorylate
ADP to make ATP.
Cells may have one or
thousands
Has two membranes



The outer is
smooth
The inner is
folded called
cristae
The inner has
enzymes for
cellular
respiration
Chloroplast
 Chloroplast are found in specialized cells like leaves
and stems.
 Other chromoplasts are found in petals of flowers
and skins of fruits

Below is a picture of plants cells with several chloroplasts
Membranes of chloroplasts
 A Chloroplast has
3 membranes
 The
outer 2 are
smooth
 The inner makes
stacks of thylakoids
Inside the chloroplasts
 The chlorophyll and other
pigments are found inside
the thylakoid membrane.

The pigments have the
ability to covert light energy
into chemical energy.
 A stack of thylakoids is
called a granum
 The matrix that the
granum is embedded in is
the stoma. It contains
enzymes for carbohydrate
synthesis
Summary of chloroplast:
 Chloroplast contain chlorophyll and other pigments
for photosynthesis. Found in certain plant cells and
algae
 They have 3 membranes. The outer 2 are smooth
and the inner one makes stacks of thylakoids. A
stack of thylakoids is called a granum. Grana are
embedded in the stroma which has enzymes for
carbohydrate synthesis.
 Below is a diagram of the thylakoid and the location
of the chlorophyll
Ribosomes
 A workbench for
protein synthesis.
 Has no membranes
and is made of
rRNA and proteins.
 Cells can have
thousands
The Cytomembrane (Endomembrane) system
 Are the organelles derived from one another, or
continuous with one another?
 Evolved from the folding in of the plasma membrane
 This includes the nuclear membrane, the E.R., the
golgi apparatus, vesicles and lysosomes.
Diagram:
Cytomembrane (Endomembrane) Theory
Endosymbiosis Hypothesis
 The mitochondria and
chloroplast evolved from
prokaryotic cells
engulfing other
prokaryotic cells. This is
called the endosymbiosis
hypothesis
 Evidence for
Endosymbiosis




Has its own circular DNA
Has ribosomes
Can divide on its own
Synthesizes proteins
Note: Flagella also thought
to have come from
endosymbiosis
(hypothesis proposed by
Lynn Margulis but never
accepted)
This is called the endosymbiosis hypothesis
 This shows how endosymbiosis may have occurred
with a prokaryotic cell taking up residence in another
prokaryotic cell
 Mitochondria is in
this diagram
 Chloroplast in the
next diagram