Cytology Part I Flashcards
The basic structure of the plasma membrane includes:
- Bilipid layer
- Proteins
- Carbohydrates
- Cholesterol
Name the two parts of a phospholipid
Hydrophilic head and hydrophobic tails
Name the 5 functions of a protein in the plasma membrane
Transport, enzyme, receptors, recognition, attachment
Why is the head of a phospholipid hydrophilic
It contains a phosphate group which gives it polarity (electric charge)
Why is the tail of a phospholipid hydrophobic
The tails are made up of fatty acids that have no electrical charge. No electrical charge = no attraction = repulsion
Describe a protein’s role as a transport
Passageway to move across the bilipid layer
Describe the role of a protein as an enzyme
A catalyst that increases the ability of a chemical reaction to take place
Describe the role of a protein as a receptor
Sends chemical messages that can attach to a protein - receiving the message can trigger events.
Describe the role of a protein in recognition
Identifying cells - proteins act as cell identity markers
Describe the role of protein in attachment
Cell to cell adhesion
What is the role of a carbohydrate in the plasma membrane?
Contributes to cellular recognition (with proteins) and ability of cells to interact with each other
What is the role of cholesterol in the plasma membrane?
Effects the fluidity of the membrane
Describe how a leak channel / pore is structured
A hollow center for molecules to fit through and move across the cell membrane - very specific to size, shape, and charge
Describe how a gated channel is structured
Has a gate that can close and open - turns membrane permeability on and off
Describe how a facilitated transporter is structured
“Revolving door” - a molecule interacts with the facilitated transporter, the transporter will flip positions from and close behind and open in front.
Describe how active transport “pump” is structured
Similar to facilitated transporter but required energy. ATP allows for a molecule to be transported. ATP then turns to ADP.
Name the two passive modes of transport
Diffusion: movement of molecules dissolved in water
Osmosis: movement of water
Name the two active modes of transport
Pump
Bulk transport
Describe a tight junction
Creates a seal that runs around the perimeter of the cell and prevents leakage between cells
Describe a desmosome
Gives cells strength - acts as a single point of attachment between and within cells
Describe gap junctions
Communication between cells - pores line up to create a continuous passageway between cells which allows cells to behave similarly
Describe the structure and function of cilia
“Like fingers” - has interior content of microtubules that can slide back and forth causing cilia to generate movement outside of the cell
Describe the structure and function of microvilli
Passive folds that add tot he amount of surface area in the cell
Describe flagella
Sperm - flagella forms the tail of the sperm cell
