Unit 2 lecture 1 9/19/22 Flashcards
the phospholipid bilayer is a _______ barrier, meaning only certain compounds can cross it
Selectively permeable
_________ are the most abundant compounds in the cell membrane
Phospholipids
Phospholipids are _______ meaning the have strongly hydrophilic and hydrophobic ends
Amphipathic
the bilayer and constituent parts move and behave in a fluid behavior, described by the _______
Fluid mosaic model
______ (cholesterol) and unsaturated fatty-acid tails help the membrane retain its fluid behavior
Steroids
Two broad categories of proteins are:
1. _____
2. _____
1.Integral proteins
2.Peripheral proteins
______ penetrate the hydrophobic interior of the bilayer
Integral proteins
proteins that go all the way through the membrane and are known as _______
transmembrane proteins
______ are not embedded in the bilayer, but are often bound to the surface by integral proteins and can exist on both side of the cell membrane
Peripheral proteins
Cell-cell recognition is often mediated by molecules containing carbohydrates on the extracellular surface which are generally short branched chains of 15 or less sugar monomers, they may be bound to ________ or to ________
1.lipids (Glycolipids)
2.proteins (Glycoproteins)
the cell membrane is ________ with molecular properties impacting how compounds cross
Selectively permeable
_______compounds can cross the interior of the membrane with relative ease
Hyrdophobic
______ compounds struggle more, even very small molecules like water
Hydrophilic
Hydrophilic substances can avoid the hydrophobic interior of the membrane by passing through _____
Transport proteins
Examples of transport proteins include:
1. ____
2. ____
1.Channel proteins
2.Carrier proteins
_______ function by having a hydrophilic channel that certain molecules use as a tunnel
Channel proteins
______ allow the passage of single file water molecules at the rate of 3 billion per second
Aquaporins
______ are specific to certain compounds, and undergo a shape change that facilitates their movement across the membrane so they can dump their cargo on one side or the other
Carrier proteins
_______ process by which molecules space themselves out
Diffusion
The rate of diffusion is driven by a _______ which occurs when two areas have differing concentration
concentration gradient
Diffusion of a substance across a biological membrane constitutes ______ because it requires no energy
Passive transport
The movement of water across a selectively permeable membrane is a particular type of diffusion called ______
Osmosis
The concept of is ______ how a surrounding solution will influence the movement of the solvent (water)
Tonicity
In ______ the concentration of solutes is the same inside the cell, as it is outside
isotonic environments
In _______ there is a higher concentration of solutes outside the cell than inside causing the cell to shrink
Hypertonic
In _______ there is a higher concentration of solutes inside the cell than outside causing the cell to become swollen
Hypptonic
Proteins aide the passage of certain certain hydrophilic compounds through the membrane along the osmotic gradient in a process known as _______
Facilitated diffusion
_______ requires some energy input and exclusively relies on carrier proteins to move substances against a concentration gradient
Active transport
In animal cells, concentrations are _______ inside for Na+
much lower
In animal cells, concentrations are ______ for K+
much higher
The combination of moving against the gradient and a charge gradient is known as ____
electrochemical gradient
Some transport proteins couple the diffusion of a particular solute across a gradient with the movement of another compound against its gradient, a phenomenon known as ______
cotransport
_______ carries compounds out of the cell in bulk through the usage of vesicles
Exocytosis
_______ carries compounds in of the cell in bulk through the usage of vesicles
Endocytosis
_______ are produced in small amounts, and influence behavior of cells in different regions of the body
Hormones
Cell signaling occurs in three, distinct stages:
1._____
2._____
3._____
1.Reception
2.Transduction
3.Response
______ is the detection of some signaling molecule originating from outside the cell
Reception
Reception is dependent upon _____ which are molecules that specifically bind to other molecules
Ligands
_______ is the process by which signals are converted to a form that can bring about a specific response involving protein phosphorylation and dephosphoryltion
Transduction
