CMB Lecture 3 Flashcards
(23 cards)
Bilayer is __ thick
8nm
More proteins in _ layer
cytolpasmic
Proteins that span hydrophobic regions are called
Amphipathic protein, both hydrophobic/hydrophillic
Types of membrane transport:
Passive, Active, Exocytosis, Endocytosis,
Unsaturated hydrocarbons will ____
bend, making the membrane fluid. This pushes away neighboring lipids, cannot solidify, helps retain fluidity in low temps.
Cell-cell recognition:
Done by glycoproteins with carbohydrates
Attachment to the cytoskeleton and ECM
Done by glycoprotein
Types of junctions in animal tissues:
Tight junctions, Desmosome, Gap junction
Cell junction in plant tissues
Plasmodesmata
Tight junction functions:
Prevent fluid from moving across layer of cells, water tight
Desmosome functions:
Anchoring 2 cells together tightly, Holds muscle cells together
Gap junction:
Made up of connexin proteins, forms cylinder enabling communication between cells, only allows small ions, sugars ,AA through channel
Plasmodesmata
Allow small proteins and n.a. between cells
Passive transport of small molecules types:
Diffusion, facilitated diffusion
Active transport:
Na/K+ pump
Passive membrane transport moves energy requirements?
Spontaneous, no energy expenditure by cell required, moves from high conc. to low conc.
Which molecules can diffuse with no protein?
Small non polar molecules (O2) and small uncharged polar molecules (CO2)
Faciliated diffusion: which molecules can move passively through membrane when assisted by transport membranes?
Hydrophillic molecules.
Which protein open and closes for diffusion?
Carrier protein
What is active membrane transport?
Move against the conc gradient, usually reuqires ATP, all carrier protein eg/K pump
Features of membrane transport proteins (x4)
Provides selectivity, can increase rate of transport, continuously recycled, however, rate of transport is limited by number of proteins.
How does transport of large molecules across cell membrane occur?
Exocytosis, and endocytosis
List the types of endocytosis
Phagocytosis, pinocytosis, and receptor mediated endocytosis.
