6+7 - The Cell Flashcards
How do cells differentiate in size?
all the same size
What are microvilli? What is their function?
Microvilli = Cells making up the lining of our small intestines have small extensions on their plasma membranes.
- This increases the cell surface area aiding in their primary function of absorption of digested nutrients.
What are the 3 eukaryotic cell components?
- plasma membrane
- nucleus
- cytoplasm
What is the plasma membrane?
Semi-permeable membrane separating the intracellular environment from the extracellular environment
What is the function of the plasma membrane?
Aids in homeostasis by controlling passage of substances into and out of the cell
What is the structure of the plasma membrane?
Phospholipids self-orient into double layer as the hydrophobic tails attract one another
What is dispersed amongst the lipid bilayer of the plasma membrane?
membrane proteins
What are the 2 main components of the plasma membrane?
1) phospholipids
2) proteins
What is the function of phospholipids within the plasma membrane?
make plasma membrane pliable so cells do not break when we move
What is the nucleus and its function?
Large organelle housing the DNA of the cell (chromatin) enclosed by a double membrane (nuclear envelope)
What is the nucleolus and its function?
- Darker region within the nucleus
- Function is to make ribosomes
What defines wether or not something is considered an organelle?
if it is enclosed in membrane
What 2 forms can DNA exist in?
- Chromatin – loose strands
- Chromosomes – DNA that is condensed at the start of cell divisions
What is cytoplasm?
Included the fluid (cytosol) and all of the organelles that exist outside the nucleus that are enclosed by the plasma membrane
What makes up the cytoplasm?
A. RIBOSOMES
B. ENDOMEMBRANE SYSTEM
C. ENERGY TRANSFORMING ORGANELLES
D. PEROXISOMES
E. CYTOSKELETON
Why do phospholipids membranes pinch off?
to form a vesicle and then fuse with another for the transportation of materials from one organelle to another or for release of cell products outside of the cell
What is the rough endoplasmic reticulum and why is it called rough?
highly folded membranous organelle that surrounds the nucleus
called rough because its surface is studded with ribosomes
What are the functions of the rough endoplasmic reticulum?
- Make and process protein that will be exported out the cell
- Make plasma membrane components (phospholipids and proteins)
What is the smooth endoplasmic reticulum? Why is it called smooth?
- Continues out from the rough ER
smooth - ot studded with ribosomes
What are the functions of the smooth endoplasmic reticulum?
- Synthesize lipids
- Detoxification of drugs and poisons
- Storage of calcium ions
What is the Golgi apparatus?
highly folded membranous organelle that receives proteins and lipids from the ER via transport vesicles
What is the function of the Golgi apparatus?
- Modifies and stores proteins and lipids until needed
- Send them out in transport vesicles to be used by the cell or to be exported from the cell
What are lysosomes?
- Organelles containing digestive enzymes (hydrolases) for breaking down macromolecules and damaged organelles within cells
What processes are lysosomes involved in?
autophagy and phagocytosis
What is autophagy?
- Destruction of dysfunctional cell components and cell debris
- Molecular components released from the process can be reused by the cell to make new structures