Week 2/3: Cells & Cellular Function Flashcards
Histology
Study of tissues
Endocytosis
Cell membrane engulfs larger molecule to bring into cell
Exocytosis
cell vescicular process that releases material outside of cell
Endocytosis Types
- Phagocytosis
- Pinocytosis
- Receptor Mediated Endocytosis
Phagocytosis
“Cell-Eating” is the process of engulfing particles such as bacteria, dust, and cellular debris. Only occurs in specialized cells.
Example: Neutrophils (a class of white blood cells) protect the body from infection by phagocytozing and killing bacteria
Phagosome
a vesicle in the cytoplasm surrounded by a unit membrane- this forms via phagocytosis
Pinocytosis
“Cell Drinking” is the process of taking in droplets of ECF (extracellular fluid) containing molecules of some use to the cell. The process begins as the plasma membrane becomes dimpled, or caved in at points. These pits separate from the surface and form pinocyotic vesicles.
Pinocyotic Vesicles
a vesicle in the cytoplasm that forms via pinocytosis
Receptor Mediated Endocytosis
A more selective form of phago or pino-cytosis where receptors identify matter that the cell wants to take in. this limits the number of unnecessary matter that the cell consumes.
Semipermeable
Allows some things through but not others
Cell Membrane
Function: Controls what molecules enter and leave the cell, example: food & oxygen molecules must enter the cell AND waste product needs to be released.
Analogy: Gates/ Doors
Extracellular Fluid (ECF)
All body fluids not contained in the cells. Also called tissue or interstitial fluid
Intercellular Fluid
Fluid within the cell that surrounds the cytoskeleton, organelles, and inclusions. Also called the Cytosol.
Organelles
Internal structures within cells that carry out a specific metabolic task
Membranous Organelles
- nucleas
- mitochondria
- lysosomes
- peroxisomes
- endoplasmic reticulum
Organelles without membranes
- Ribosomes
- Proteasomes
- Centrosomes
- Centrioles
- Basal Bodies
Nucleas
Appearance: largest organelle in most cells and is surrounded by double membrane.
Function: genetic control center of cell; directs protein synthesis & shelters the DNA
Most cells contain a single nucleas.
Analogy: control center of cell/ manager’s office.
Annucleas
cells without nucleas example: red blood cells
Multinucleas
cells with multiple blood cells, example: skeltal muscle cells, liver cells, bone dissolving cells.
Nuclear Envelope
Double membrane that surrounds the nuclease
Nucleaplasm
Material in the nucleus
Chromatin
Fine threadlike matter composted of DNA and protein. Encased within the nucleaplasm
Nucleioli
Produces Ribosomes
Endoplasmic Reticulum types
- Rough E.R
2. Smooth E.R
Rough E.R
Location: extensive sheets of pparelle mebranes with ribosomes on outer surface.
Function: Protein synthesis and manufacturer of cellular membranes
Smooth E.R
Location:Branching network of tubules with smooth surface
Function: Lipid & hormone syntesis, detoxification, calcium storage
Endoplasmic Reticulum
Protein synthesis and manufacturer of cellular membranes
Analogy: Conveyer Belts
Ribosomes
Appearance/ Location:free in cytosol, on surface of rough ER and nuclear envelope, and inside nucleus & mitochondria
Function: Interpret genetic code and synthesize polypeptides
Analogy: Machines
Lysosomes
Trash disposal of cell- contains digestive enzymes that break down waste.
Package of enzymes, example: in the liver, lysosomes break down glycogen to be converted into glucose.
Analogy: Janitor
Autolysis vs Autophagy
Autolysis: the digestion of surplus cells by their own lysosomal enzymes. Some cells are meant to do a certain job and then destroy themselvesAlso known as cell suicide. Example: following pregnancy, the uterus will shrink considerably.
Autophagy: digestion and disposal of surplus or nonvital organelles in order to recycle their nutrients to more important cell needs
Golgi Complex/ Apparatus
Appearance/ location: near the nucleus, often with many golgi vesciles nearby.
Function: Delivery system of the cell- collects/ modifies/ and packages molecules into vesicles within the cell.
Analogy: post office/ mail room
Mitochondria
ATP synthesis
Analogy: power plant/ electrical room