Fundamentals of cell biology Flashcards
Why is cell size limited?
as it incr, takes longer for material to diffuse from cell membrane to interior of cell
Surface area-to-volume ratio; as a cell incr in size, volume incr 10x faster than surface area
What are eukaryotic cells?
Possess a membrane bound nucleus
more complex than prokaryotic cells
Compartmentalise many cellular functions within organelles and endomembrane systems
Possess a cytoskeleton for support and to maintain cellular structure
what are the functions of the cell membrane
Physical isolation (membrane rupture can lead to cell death
Regulatiion and exchange with the environment (control of ions)
Cell-cell communication
Sensitivity (receptors)
Structural support
Contains lipids (phospolipids), proteins and carbohydrates
Lipids contain a hydrophilic head and hydrophobic tail
Hydrogen bonding form between the hydrophilic heads and the interior/exterior of the cell. Van der waals forces hold the two layers together.
What is the cytoplasm in a eukaryotic cell?
Region between the nucleus and cell membrane
Cytosol (intracellular fluid) - contains dissolved nutrients, ions, proteins, and waste
small amount of carbs and large reserves of amino acids and lipids
organelles - structures that perform specific functions
What is the cytoskeleton?
Internal protein framework of threadlike filaments: actin, microfilament, microtubules
What is the roles of the cytoplasm?
Maintenance of cell shape
Cell motility
Mechanical support
Intracellular transport of organelles
Cell division
What is the microvilli?
Small, finger shaped projections of the cell membrane
What is the centrioles?
Short cylindrical structure composed of triplet microtubules
Very important for division
Forms base of cilia.
What is the cilia?
Antennae like structures consisting of 9 doublet microtubules
What is the flagella?
Similar structure as cilia but are larger and mediate cell motility
What are ribosomes?
Organelles that manufacture proteins
What is the endoplasmic reticulum?
membranous structure connected to
nucleus
roles:
➢ Synthesis of proteins
➢ Storage of molecules
➢ Transport
What is the golgi apparatus?
5-6 flattened membranous discs responsible for synthesis of vesicles for excretion and transport throughout
What is the mitochondria?
produce molecules that can store energy for cells in the form of adenosine triphosphate (ATP)
0.5-1.0 μm in diameter
The number of mitochondria per cell can vary between 1 and several thousand. They can make up a high percentage of the cytoplasms volume
What is the role of the nucleus in eukaryotic cells?
Control centre for cellular operations
Contains all genetic information to produce 100,000 proteins.
