Unit B: Cell
structure
Animal cell
Liver Cell
Cell membrane
Nucleus
Nucleus
Nuclear pores
FUNCTIONS OF NUCLEUS:
• Nuclear membrane/envelope bilayer,
separates and contains nuclear contents
(DNA).
• Nuclear pores: allow mRNA out of
nucleus, nucleotides, nutrients &
enzymes in. They are made from
protein.
• Chromatin: Protein & DNA; form
chromosomes when cell divides.
• Nucleolus:contains rRNA and Ribosomal
proteins.
The Endoplasmic
Reticulum: ER
• Rough E.R.
• Smooth E.R.
• Studded with
ribosomes
• Site of protein
synthesis for
proteins meant
for export
• Phospholipids
made here
• Detoxifies poisons
(found in liver
cells)
• Synthesize
steroids
Endoplasmic Reticulum
Endoplasmic reticulum
Ribosomes
Function of Ribosomes
• Made from two protein subunits
and rRNA
• Some are free, found alone in
cytoplasm
• Others are attached to the RER
• Translation of mRNA into
polypeptides or PROTEIN
SYNTHESIS!
Ribosome structure:
Mitochondria
Function of Mitochondria:
• Cellular Respiration converts
energy in Glucose to ATP
• C6H12O6 + O2  CO2 + H2O +
38 ATP
• Found in large numbers in
energetic cells (sperm cells,
muscles etc.)
Golgi
apparatus
Looks like a series of
flattened sacules.
Appears close to the
cell membrane.
Golgi
•Packages, modifies
and stores molecules.
•Forms transport or
secretory vesicles
•Involved in export of
proteins through
exocytosis.
•Draw diagram page
2 in green book
exocytosi.ram
Lysosomes
Lysosomes:
• Contain hydrolytic enzymes (help
to perform hydrolysis) for
digesting molecules.
• These special vacuoles merge with
another molecule containing
vacuole for cell digestion.
• Called “suicide sacs”, contents
could destroy cell!
Microtubules, cytoskeleton
Cytoskeleton
• Many protein filaments (actin
filaments and microtubules) help
organize and anchor cell parts.
cilia
Cilia and flagella microtubule
arrangement 9+2
Function of cilia and
flagella:
Cilia:
•Line the respiratory passages and sweep
mucus upwards.
•Line the oviducts to transport ovum to
uterus
•Flagella: Propel sperm
towards the ovum.