Lecture 2 Flashcards
What are integral proteins
They are embedded in the membrane (partially or fully)
What are peripheral proteins
On the outside or inside of the membrane and may be attached to integral proteins or phospholipids
Functions for cytoskeleton in the cellular structure
- helps maintain cell shape and structure
- helps maintain internal organization
- essential for movement and cell division
- dynamic - changes to meet needs of the cell
Microtubules what is it and what is the motility
A twisted helix made of tubulin, that make up a tub like structure which is important to resist compression which helps maintain cell shape.
For motility it uses a form of flagella and cilia for organelle motility
Microfilaments
- what are they
- what is their motility
It is a twist rope like structure made of tiny actin subunits which are important for resisting tension. These microfilaments form a cortical network beneath plasma membrane (for protiens to attach to)
The motility of movement is the actin and myosin interactions for muscle contraction of the sliding filament theory
Intermediate filaments
- what are they
- what are their motility
They form more permanent structures, it is a cable twisted structure made of keratin protiens coiled together (hard to break). They help anchor organelles and important in cell adhesion. Because they are fairly permanent structure there is no motility
Nucleus
• Contains most of the cell’s DNA
• euchromatin & heterochromatin
• Contains nucleolus
• makes rRNA & ribosomal subunits
• Surrounded by nuclear envelope • Double membrane
• Continuous with ER.
Interconnected systems that include in the endomembrane system
Endoplasmic reticulum
Golgi apparatus
Vesicles
Smooth ER
• Lacks ribosomes on surface
• Stores calcium ions (used as a signal within cell)
• Synthesises lipids
• Metabolises carbohydrates
• Detoxification processes
Rough ER
• Covered with ribosomes on outer surface
• Role in protein synthesis
• Proteins enter lumen of rER
• Proteins are modified, folded & packaged into vesicles
• Transported to Golgi
Golgi Complex
• Series of membrane sacs and vesicles
• Vesicles from ER arrive at cis face
• Proteins modified, glycosylated, sorted into vesicles
• Vesicles leave from trans face
Membrane transport = passive transport
No energy is required as substances move down the concentration gradient, this could. Be through simple diffusion with small molecules, that are either hydrophobic and have no charge, or it could use facilitated diffusion with membrane protiens as channels or carriers.
What is active transport
Requires energy, moves substance against their conc grad and will use transport protiens or e.g Na+/K+ pump
What are the two types of exocytosis (bulk movement) and what is it
Transports materials out of cell or to cell surface
• Constitutive exocytosis releases ECM proteins
• Regulated exocytosis releases signals e.g. hormones & neurotransmitters
