Plasma membrane Flashcards
Biomembranes include ____ and ________
Cell membrane & organellar membrane
What 3 substances constitute cell membrane ?
Lipids , proteins , carbohydrates
Human RBCs ( erythrocytes)
percentage of substances in cell membrane
Lipids = 40 percent
Proteins = 52 percent
Carbohydrates = 8
True or False
Structurally , cell membrane of prokaryotes & eukaryotes is similar
TRUE
Who gave the fluid mosaic model & when ?
Singer & Nicolsan ; 1972
What is the fluid mosaic model ?
Proteins in mosaic pattern arranged in phospholipid bi-layer
Lipid other than phospholipid present in cell membrane.
Cholestrol
Cholestrol function
Provides strength
Types of Proteins
Intrinsic ; Peripheral
Types of Intrinsic protein
totally buried ; partially buried
Types of totally buried proteins
Tunnel ; Carrier
Carbohydrates in plasma membrane are also known as ________
Oligosaccharides
Oligosaccharides meaning
Oligo = small => small chains
Saccharides = sugar
Types of carbohydrates in cell membrane
Glycoprotein ; Glycolipid
Glycoproteins are carbohydrates associated with
Proteins
Glycolipids are carbohydrates associated with
Lipids
2 components of phospholipids
Phosphate ion ; lipids
Which component of phospholipid is polar ?
Phosphate ion ( PO4 3- )
Which component of phospholipids is non - polar ?
Lipids
True or false
SPhospholipid is an amiphipathic molecule as it has dual nature ( both polar head & non-polar tails)
TRUE
Straight tail refers to
Saturated fatty acid
Bent tail refers to
Unsaturated fatty acid
Tails are ________ while head is _______
Hydrophobic ; hydrophilic
Head is made up of
Phosphate ion
Carbs are always found in which aspect of plasma membrane ?
Outer
Carbs are always found in association with
Lipids , proteins
__________nature of ______ enables ___________ of ________- and ability to move is measured in terms of its __________
quasifluid ; lipids ; lateral movement ; proteins ; fluidity
functions enabled by fluid nature
Cell growth , intercellular junction , endocytosis , secretion , cell division
Proteins are classified on the basis of
ease of extraction
extrinsic proteins are involved in
Enzymatic activity
Proteins which are tightly bound with phospholipids are
Intrinsic proteins
Carbs are involved in
Cell to cell recognition
give 2 examples of cell to cell recognition
Fertilisation ( sperm & ova) ; blood group antigens
neutral solutes transport through which process & through which part of plasma membrane ?
Simple diffusion ; phospolipid bilayer
Two types of transport are
active & passive
2 types of passive transport are
Facilitated diffusion , simple diffusion
Passive transport is ________ the concentration gradient& does not require ______. It is called __________ process.
(along ; energy(ATP) ; down - hill
active transport is ________ the conc. gradient & requires ________ . It is called __________ process.
against ; energy( ATP) ; uphill
Osmosis of water & ions takes place through
tunnel proteins
Transport of polar molecules , large molecule , amino acids takes place through
Carrier proteins
Active transport like Na+ K+ pump takes place via
Carrier(pump) proteins
Bulk transport involves two processes which are
Endocytosis ( taking in ) ; Exocytosis / Emiocytosis ( throwing out/egestion of waste materials)
Cell taking in solid complex materials in form of vesicles called _______ is called _________
phagosome , phagocytosis
Cells taking in liquid material in form of vesicles called _________ is called ________
pinosomes ; pinocytosis
