Eukaryotic + Prokaryotic Cells Flashcards
Key features of a eukaryotic cell?
- Has membrane bound organelles
- Complex
- Big ribosomes
- If it has a cell wall = made of cellulose
Around what size is a eukaryotic cell?
20+ micrometres
What are the two main types of eukaryotic cell?
- Animal cell
- Plant cell
List the organelles common to all eukaryotic cells
- Nucleus
- Ribosomes
- Rough Endoplasmic Reticulum
- Smooth Endoplasmic Reticulum
- Mitochondria
- Golgi Apparatus
- Lysosome
- Centriole
- Cytoplasm
- Cell membrane
Describe the nucleus 3
- Enclosed by double membrane nuclear envelope
- Contains nucleolus
- Contains chromatin/chromosomes of DNA
What is the nuclear envelope composed of?
Two membranes containing many pores, allowing substances to move between cytoplasm and nucleus
What is the nucleolus?
- Dense body where ribosomes are made
What are the functions of the nucleus? 3
- Where ribosomes made
- Contains instructions on protein making in genetic material
- Controls cell activities through controlling DNA transcription
What are lysosomes?
Spherical sacs bound by a single membrane keeping digestive enzymes inside (lysozymes) separate from the cytoplasm
What are the 3 functions of lysosomes?
- Digest invading cells
- Destruction of whole cells when old cells replaced/during development
- Breakdown of unwanted structures in cells
What are ribosomes?
Very small organelles made of RNA and proteins
What 2 places are ribosomes found?
- On the Rough Endoplasmic Reticulum (ReR)
- Free floating
Are ribosomes surrounded by a membrane?
No
What is the purpose of the ribosomes?
Protein synthesis
What is the Rough Endoplasmic Reticulum made of?
A system of:
- Interconnected
- Membrane bound
- Fluid Filled
- Flattened sacs
- Outer surface: covered in ribosomes
What are the 2 functions of the RER?
- Folds and processes proteins from the ribosomes
- Transports proteins from ribosomes to other parts of the cell
What is the Smooth Endoplasmic Reticulum made of?
A system of:
- Inerconnected
- Fluid filled
- Membrane bound
- Flattened sacs
- No ribosomes on the outer surface
What is the function of the Smooth Endoplasmic Reticulum?
Synthesis of lipids and steroids (e.g reproductive hormones)
What is the Golgi Apparatus?
Group of flattened fluid filled membrane bound sacs
How is the Golgi Apparatus formed?
Fusion of vesicles from the ER
What are the 3 functions of the Golgi Appartus?
- Processes and modifies proteins and lipids
- Package proteins and lipids in vesicles for transport
- Makes lyosomes
What do mitochondria look like?
Oval shaped organelles with a double membrane
What does the inner membrane of the mitochondria look like and why?
Folded to form finger like projections (cristae) to increase surface area
What is contained inside the mitochondria?
The matrix - containing respiration enzymes
What is the function of the mitochondria?
Site of ATP production
Where are mitochondria found in large numbers?
Active cells requiring a high amount of energy
What are centrioles?
Small hollow cylinderical tubes made of a ring of 9 protein microtubles
What are the 3 functions of the centrioles?
- Seperation of chromosomes in cell division
- Transport within cell cytoplasm
- Can develop into cilia and flagella
How are centrioles found?
In pairs
Give the steps of protein processing
- Proteins made at the ribosomes
- Enter rough ER lumen
- Protein move through RER assuming 3D shape en enroute as they are folded and processed
- Vesicles pinched off the rough ER contain the protein
- Form flattened sacs of the Golgi Apparatus
- Proteins undergo further processing at the Golgi Apparatus e.g addition of a carbohydrate to form glycoprotein
- Secondary vesicles pinched off the GA contain the modified protein
- Become part of vesicle membrane
- Vesicle fuses with cell surface membrane releasing protein
What defines a prokaryotic cell? 6
- Single celled organism
- No nucleus
- No membrane bound organelles
- Small ribosomes
- Cell wall: murein
- All have a plasmid
- Some have a flagella and a capsule
What is DNA in eukaroyotic cells like?
- Long linear
- Double helix
- Folded around histones
- Folded into chromosomes
- Found in nucleus
What is DNA in prokaryotic cells like?
- Shorter and circular
- No proteins/histones
- No nucleus
- Can be found in plasmids
Which eukaryotic organelles contain their own DNA?
- Mitochondria
- Chloroplasts
