Plasma Membrane

Question 1

What is a cell?

Answer 1

• All living things made up of cells
• Basic unit of life
• Each cell surrounded by a cell membrane
• Cells have organelles that perform different functions and are essential for cell and organism survival

Question 2

Two types of cells

Answer 2

Prokaryotic
- Simple structure, no nucleus, small size
Ex. bacteria and archaea
- Huge importance in vet med
- Pathogenic bacteria cause infections in animals
- Bacteria in gut microbiome
- Use of antibiotics for treatment and selective pressures leading to antibiotic resistance

Eukaryotic
- Complex structure, membrane bound nucleus, larger size
- Important in vet med
- Understand disease pathogenesis at cell level
- Knowledge of cell bio and function to inform diagnosis and treatment

Question 3

cell form=function

Answer 3

Each cell type has different shapes and characteristics that result in different functions
Ex. neurons
Ex. ciliated cells in respiratory system

Question 4

Lipid bilayer and plasma membrane

Answer 4

• Composed of two layers of phospholipids
• Hydrophilic phosphate heads (polar)
• Hydrophobic lipid tails (non-polar)

Also contains:

Membrane proteins
- Integral proteins embedded within the lipid bilayer
- Peripheral proteins- loosely attached to the membrane surface

Cholesterol
- Interspersed within the lipid bilayer to modulate membrane fluidity and stability

Glycolipids and glycoproteins
- Carbohydrate chains attached to the lipids and proteins on the cell surface (glycocalyx)
- Contribute to cell recognition, adhesion, and signalling

Question 5

Functions of the plasma membrane

Answer 5

• Regulates the passage of molecules in and out of cell
• Enables cell adhesion and recognition, crucial for tissue formation in development
• Provide structural support to maintain cell shape and facilitates movement
• Facilitates communication and signal transduction between cells

Question 6

Things to consider when Identifying plasma membrane in tissue

Answer 6

• resolution of image
• staining method
• tissue cutting is 2D from 3D object
• what else is surrounding the cell

Question 7

Subcellular organelles

Answer 7

• Nucleus- houses DNA, controls cell division and replication
• Mitochondria – powerhouse of the cell
• Endoplasmic reticulum- Rough (protein synthesis, ribosomes are attached to help with transport through rER), smooth (synthesizes cholesterol, steroids, carbohydrates, lipids, phospholipids
• Golgi apparatus (modifies, sorts, and packages proteins and lipids), vesicles, secretory granules
• Degradation organelles (lysosomes and peroxisomes)
• Lipid droplets