Cells Flashcards
What are the three major regions of the cell?
- plasma - controls what materials move into and out of the cell
- nucleus - controls the cells activities
- cytoplasm - contains cytosol and organelles
What is cytosol?
Fluid between the membrane and the nucleus
What are organelles?
Structures that perform specific cell functions
What is mitochondria?
- double membrane bound organelle that produces ATP (energy)
Mitochondria have their own?
RNA and DNA and can self replicate
What are ribosomes?
- Sites for protein synthesis
What are the two types of ribosomes?
- free floating in the cytosol and produce proteins for use in the cell
- attached ribosomes on the rough ER
What are the three functions of ribosomes on the rough ER?
- produce proteins for export from the cell
- for incorporation into the plasma membrane
- or incorporation into other organelles
What does ER stand for ?
Endoplasmic reticulum
What is endoplasmic reticulum?
Flattened membrane sacs that are continuous from the nucleus membrane to the cell membrane
What are the two types of ER?
Rough and smooth
Rough ER has?
Ribosomes studded within it and participates in protein synthesis
Smooth ER has?
No ribosomes in it and doesn’t participate in protein synthesis, it produces phospholipids, fats and steroids which are used for new plasma membrane and production of some hormones.
What do both rough and smooth ER do?
Produce hormones
What does the smooth ER do in liver cells?
- detoxifies harmful substances (e.g alcohol and some drugs)
- release of glucose into blood from glycogen stores
What does the smooth ER do in skeletal and cardiac muscle cells?
- stores calcium needed for muscle contraction
- known as the sarcoplasmic reticulum
What is the gogli complex made up of?
Up to 20 flattened plate-like structures known as cisterns
What does the gogli complex do?
Processes, sorts and tags cell products for distribution and secretion
Where does the gogli complex receive its proteins from?
The rough ER
What does the transport vesicle do?
Takes proteins from the rough ER to the entry point of the gogli complex
What are lysosomes?
Membrane bound vesicles containing powerful digestive enzymes formed by the rough ER
What do lysosomes do? (3 points)
- breakdown old organelles for recycling
- breakdown harmful substances entering cells
- rupture of lysosomes leads to breakdown of cells (autolysis)
What is the cytoskeleton?
The skeleton of the cell
- provides structure and strength to the cell and aids in movement
What are the three types of cytoskeleton?
- microfilaments
- intermediate filaments
- microtubules
What do microfilaments do? (3 points)
- Help the cell move (they are abundant in muscle cells)
- maintain its shape
- stop the cell from being crushed
What do intermediate filaments do? (2 parts)
- Anchor things in place
- stop the cell from tearing apart
What do microtubules do?
Organelles hang off the microtubules and allow the organelles to move about the cell
What are three types of cellular extension?
- microvilli
- cilia
- flagella
What do microvilli do? (3 points)
- finger like projections extending from the cell surface
- increase surface area of the cell membrane
- better developed in cells specialised for absorption
What do cilia do? (3 points)
- hair like extensions of the cell membrane involved in movement
- short, numerous and are found on the surface of cells
- move and sweep mucous with trapped dust away from the cell surface
What do flagella do? (2 points)
- extension of the cell membrane involved in movement
- long, usually singular and moves the entire cell. Only sperm in the human body.
Cell diversity occurs because?
Cells having different numbers and types of each organelle
