Cells and Organelles Flashcards
What are the different components of the plasma membrane
Phospholipids, carbohydrates, proteins and cholesterol
Function of cholesterol in the plasma membrane
Maintain fluidity and stability of membrane
Function of carbohydrates in the plasma membrane
Allow cell signalling and recognition
Describe the structure of the nuclear membrane
Bilayer
Outer layer is continuous with endoplasmic reticulum
Inner layer is continuous with nuclear lamins
Nuclear pores control entry/exit of the nucleus
What is the function of nuclear lamins and what part of the cytoskeleton do they fall under
Maintain structure of the nucleus
Involved in chromatin organisation
Lamins are intermediate filaments
Function of peroxisomes + some examples
Involved in oxidative reactions eg. lipid oxidation, bile biosynthesis
Function of lysosome
Breakdown of old, unwanted and foreign particles
Describe the structure of the mitochondria
Two membranes with an intermembrane space
Inner membrane creates protrusions called cisternae
Inner space is called matrix
Contains ribosomes involved in protein synthesis
How does mitochondria participate in apoptosis
Apoptosis signals cause release of Bcl12 which causes the release of Cytochrome C, which is usually in mitochondria, into cytoplasm where it activates caspase cascade
Functions of the cytoskeleton
Maintaining cell shape and structure Allow for organelle movement Allow for cell attachment to other cells and ECM Helps cell resist mechanical stress Support fragile plasma membrane
What are the three types of cytoskeleton
Microfilaments
Intermediate filaments
Microtubules
What protein makes up the microfilament + its motor protein
Actin and motor protein myosin
Key functions of microfilaments
Forming extracellular structures eg. microvilli and stereocilia
Support membrane allowing for cell contraction or change in shape
Create membrane extensions eg. lamellipodia and filopodia allowing cell motility
Form contractile ring in cytokinesis
What are some of the proteins found in intermediate filaments
Keratin
Desmin
Vimentin
Lamins
What protein makes up microtubule + its motor proteins
Tubulin
Motor proteins dynein and kinesin
Function of intermediate filaments
Provide structural integrity to the cell