2. Organelle Structure and Function Flashcards
What is the nuclear membrane?
Double membrane that controls entry/exit of materials to and from the nucleus.
What are nuclear pores?
Holes in the nuclear membrane that allow mRNA and ribosomes to exit.
What is the nucleoplasm?
Jelly-like material that makes up the bulk of a nucleus.
What is the nucleolus?
Small spherical region in a nucleus that contains ribosomal RNA (rRNA) and manufactures ribosomes.
What is chromatin?
An uncondensed complex of DNA and protein.
What does chromatin condense into prior to cell division?
Chromosomes
What is the function of a mitochondrion?
The site of cellular respiration.
In which eukaryotic cell would you not find a nucleus and why?
Red blood cells
To give more room to carry oxygen
Which cells contain many mitochondria?
Metabolically active cells such as:
Muscle cells
Intestinal epithelial cells
Sperm cells
or in cells where active transport takes place
How are mitochondria adapted to carry out their function?
- Cristae - extensions of inner membrane provide large surface area for respiration reactions to take place.
- Matrix - inner space contains ribosomes, and DNA so that respiratory enzymes can be quickly produced when needed.
What is the function of a chloroplast?
To carry out photosynthesis
Carbon dioxide + Water –> Glucose + Oxygen.
Which plant cells do not contain chloroplasts and why?
Root hair cells - no sunlight underground.
What is the chloroplast envelope?
A partially permeable double membrane that surrounds a chloroplast.
What are thylakoids?
Flattened sacs found within a chloroplast that contain chlorophyll.
What is chlorophyll?
The green pigment found inside the thylakoids of chloroplasts that captures light energy.
What are grana?
Stacks of thylakoids.
The place where the 1st stage of photosynthesis takes place (light absorption).
What is the stroma of a chloroplast?
The fluid filled space within a chloroplast.
Where the 2nd stage of photosynthesis takes place (sugar synthesis).
How are chloroplasts adapted to carry out their function?
- Granal membranes provide a large surface area for photosynthesis reactions to take place.
- Stroma contains enzymes for 2nd step of photosynthesis to take place (sugar synthesis).
- Contain DNA and ribosomes so can quickly produce enzymes required for photosynthesis when needed.