LUCIA ROMERO
TOPIC 3:
VOICE OF THE GENOME
1
,LUCIA ROMERO
3.1. & 3.2. EUKARYOTIC CELLS
Animal cells
Nucleus
→ Nucleus contains a nucleolus and chromatin
Nucleus: controls transcription of DNA, therefore, production of proteins
Nucleolus: makes ribosomes
Nuclear pore: allows passages of substances, e.g., mRNA can leave
Lysosome
→ Membrane bound circular organelle with no clear internal structure
Function:
1. Contains digestive enzymes that break down invading foreign cells, e.g., pathogens
2. Simply worn-out parts of the cell
Ribosome
→ small organelles with no plasma membrane. Can be found freely in the cytoplasm or attached to rough endoplasmic reticulum
Function:
1. Where protein synthesis occurs
Rough Endoplasmic Reticulum (RER)
→ Fluid filled membrane bound sacs. Ribosomes attached to the surface
Function:
Folds + processes new proteins
Smoot Endoplasmic Reticulum (SER)
→ Like rough ER in terms of structure but has no ribosomes
Function:
1. Synthesizes and processes lipids
2
, LUCIA ROMERO
Golgi apparatus
→ Also, fluid filled membrane sacs, often seen with vesicles nearby
Function:
1. Further processes the proteins
2. Packages proteins + newly synthesized lipids
3. Synthesizes lysosomes
Centriole
→ Mostly found in animal cells
Structure:
Made up of hollow tubules called microtubules (tiny protein cylinders)
Function:
Separating chromosomes during cell division
Mitochondrion
Structure:
• Double membrane, inner membrane is folded to form cristae.
• Inside is the matrix
• Where enzymes needed for respiration are found
Function:
1. To produce ATP in respiration
→ releases energy
3.3. ROUGH E.R AND GOLGI APPARATUS
Protein production & transport
Free ribosomes → make proteins that remain within the cell (intracellular proteins)
Ribosomes bound to rER → make proteins that leave the cell / become embedded in the plasma membrane (e.g., digestive enzymes + CFTR
protein)
Process
1) The rough endoplasmic reticulum helps to fold and process the proteins made
on the attached ribosomes.
e.g., a sugar chain may be added to form a glycoprotein
2) The Golgi apparatus further processes the protein
e.g., trimming the sugar chain or adding another sugar chain
It is then packaged into a vesicle ready for transport to the cell membrane or out of the
cell – exocytosis
3
TOPIC 3:
VOICE OF THE GENOME
1
,LUCIA ROMERO
3.1. & 3.2. EUKARYOTIC CELLS
Animal cells
Nucleus
→ Nucleus contains a nucleolus and chromatin
Nucleus: controls transcription of DNA, therefore, production of proteins
Nucleolus: makes ribosomes
Nuclear pore: allows passages of substances, e.g., mRNA can leave
Lysosome
→ Membrane bound circular organelle with no clear internal structure
Function:
1. Contains digestive enzymes that break down invading foreign cells, e.g., pathogens
2. Simply worn-out parts of the cell
Ribosome
→ small organelles with no plasma membrane. Can be found freely in the cytoplasm or attached to rough endoplasmic reticulum
Function:
1. Where protein synthesis occurs
Rough Endoplasmic Reticulum (RER)
→ Fluid filled membrane bound sacs. Ribosomes attached to the surface
Function:
Folds + processes new proteins
Smoot Endoplasmic Reticulum (SER)
→ Like rough ER in terms of structure but has no ribosomes
Function:
1. Synthesizes and processes lipids
2
, LUCIA ROMERO
Golgi apparatus
→ Also, fluid filled membrane sacs, often seen with vesicles nearby
Function:
1. Further processes the proteins
2. Packages proteins + newly synthesized lipids
3. Synthesizes lysosomes
Centriole
→ Mostly found in animal cells
Structure:
Made up of hollow tubules called microtubules (tiny protein cylinders)
Function:
Separating chromosomes during cell division
Mitochondrion
Structure:
• Double membrane, inner membrane is folded to form cristae.
• Inside is the matrix
• Where enzymes needed for respiration are found
Function:
1. To produce ATP in respiration
→ releases energy
3.3. ROUGH E.R AND GOLGI APPARATUS
Protein production & transport
Free ribosomes → make proteins that remain within the cell (intracellular proteins)
Ribosomes bound to rER → make proteins that leave the cell / become embedded in the plasma membrane (e.g., digestive enzymes + CFTR
protein)
Process
1) The rough endoplasmic reticulum helps to fold and process the proteins made
on the attached ribosomes.
e.g., a sugar chain may be added to form a glycoprotein
2) The Golgi apparatus further processes the protein
e.g., trimming the sugar chain or adding another sugar chain
It is then packaged into a vesicle ready for transport to the cell membrane or out of the
cell – exocytosis
3
