B2.2- Organelles and Compartmentalisation Flashcards
Is a cell wall an organelle?
no
Is the cytoskeleton an organelle
no
Is the cytoplasm an organelle?
no
Is the Nucleus an organelle?
yes
Are vesicles organelles?
yes
Are ribosomes organelles?
yes
Is the plasma membrane an organelle?
yes
Are cilia/flagella organelles?
yes
Is the golgi apparatus an organelle?
yes
Are mitochondria organelles?
yes
Are chloroplasts organelles?
yes
Are lysosomes organelles?
yes
Cell Compartmentalisation
Processes occuring inside organelles so that they don’t interfere/aren’t interfered by the chemicals in the cytoplasm or neighbouring cells.
What is an organelle?
A subcellular structure that has a membrane around it to seperate it from other parts of the cell
Do prokaryotic cells have a nucleus?
No
Do eukaryotic cells have a nucleus?
Yes
Why is it important for eukaryotic cells to have a nucleus?
It keeps the process of transcription of the DNA seperate from other things in the cell that may interfere, and ensures it finishes the process of transcription before beginning translation.
What is transcription?
When mRNA is copied from DNA
Translation
Where amino acids are joined to form polypeptide chains. Occurs at ribosomes.
Post-transcriptional modification
mRNA is modified before translation, occurs at ribosomes
What are enzymes within lysosomes responsible for?
Breaking down waste and faulty cell parts. Important that they are kept in organelles as they could destroy other cellular components.
What is Phagocytosis?
How cells engulf food particles or pathogens.
What is the technique used to isolate organelles?
cell fractionation using ultra-centrifugation
What are the 2 advantages of cell compartmentalisation?
- Reactions do not occur randomly and are not interfered with
- Enzymes cannot randomly digest cell parts
What does ATP stand for?
Adenosine triphosphate
Features of ATP
Immediate source of energy, can diffuse anywhere, releases energy very quickly.
Aerobic respiration produces large amounts of ___?
ATP
In what organelle does aerobic respiration occur?
Mitochondria
What are the 5 specialised features of mitochondria?
- inner membrane
- Cristae
- Intermembrane space
- Matrix
- Outer membrane
What is the role of the inner membrane in mitochondria?
It contains carriers and enzymes used in the end stage of respiration (the electron transport chain)
What is the role of cristae in mitochondria?
Cristae are the folds in the inner membrane. They increase the surface area for the electron transport chain.
What is the intermembrane space in mitochondria?
The space between the inner and outer membranes where protons (H+) are accumulated.
What is the role of the outer membrane in mitochondria?
To seperate the contents of the mitochondria from the cytoplasm. Has the right transport proteins for moving pyruvate into the mitochondria.
What is the role of the matrix in mitochondria?
It contains the appropriate enzymes and pH for the krebs cycle and the link reaction to occur.
Photosyntheis
The ability of plants to capture the energy of light and turn it into chemical energy of organic food molecules.
Where does photosynthesis occur?
In the chloroplasts of plant cells.
What are the 4 adaptations of the chloroplasts to be able to photosynthesize?
- Thylakoid membranes
- Thylakoid lumen
- Stroma
- Double membrane
What is the role of the thylakoid membranes in chloroplasts?
Thylakoids are membranous sacs. Their membranes have a large surface area for grater absorption of light.
What is the role of the thylakoid lumen in chloroplasts?
Thylakoid lumen is the space inside the thylakoid. It is small so that protons (H+) can accumulate.
What is the role of the stroma in chloroplasts?
The cytoplasm like region of a thylakoid. It allows enzymes involved in the Calvin cycle to catalase reactions effectively.
What is the role of the double membrane in chloroplasts?
Chloroplasts have a double membrane to isolate the reactions that happen during photosynthesis from the cytoplasm.
Nuclear envelope
The double membrane of the nucleus
What is the role of the nuclear envelope?
Keeps the reaction of the nucleus seperate from the rest of the cell.
Nucleoplasm
material inside nucleus (The cytoplasm of the nucleus)
What runs around the outside of the nuclear envelope?
Rough endoplasmic reticulum with ribosomes attatched.
Chromatin
An inactive form of DNA that helps to maintain the shape of the nucleus. (found in the nuclear membrane)
rRNA
ribosomal RNA
How many subunits do ribosomes consist of?
Two (one large and one small)
What occurs at ribsomes?
Translation of mRNA to protein
What do free ribosomes produce?
Proteins that are used inside the cell by organelles and proteins of the cytoskeleton.
What do ribosomes attached to the rough ER produce?
Proteins that can be secreted by cells.
Cisternae
The flattened sacs that make up the golgi apparatus.
What side of the cisternae sits close to the ER?
The cis side
What side of the cisternae faces the cytoplasm?
The trans side
What is produced by the rough ER?
Proteins
What is produced by the smooth ER?
Lipids
What side of the cisternae do the vesicles containing either proteins or lipids from the ER enter?
Cis
What are the four common vesicles?
Peroxisomes, lysosomes, transport vesicles and secretory vesicles
What is the role of peroxisomes?
Contain enzymes to break down fatty acids.
What is the role of lysosomes?
Contain enzymes necessary for cellular digestion and for destroying defective or damaged organelles.
What is the role of transport vesicles?
move molecules within the cell
What is the role of secretory vesicles?
contain materials that are excreted from the cell
What is a vesicle?
A small membrane bound sac used to store of transport material?
