02 - Cellular Anatomy Flashcards
A human cell consists of three major parts:
Plasma membrane, cytoplasm, nucleus
Every cell is enclosed by a thin barrier called the ___________
Plasma membrane
Plasma (cell) membrane has 2 major roles:
(a) it separates the internal cellular components from the external environment, (b) it regulates the movements of substances into and out of the cell
The ___________ describes the structure of the plasma membrane.
fluid mosaic model
The major chemical components of the plasma membrane are…
lipids and protein
This is the word to describe the area in between cells.
interstitial
How many cells are in a human body?
75 trillion cells
How many types of cells are in a human body?
200 types of cells
Function at organ level is always achieved by _________.
Function at microscopic level
Only cell in body without centriole is _____ because they don’t divide.
nerve cells
A word to describe this part of the cell is “discriminates”
plasma membrane
What percentage of the plasma membrane is lipids and proteins?
60% lipids, 40% proteins
The membrane lipids include?
phospholipids, cholesterol molecules, glycolipids
These form a lipid bilayer that is the basic framework of the plasma membrane
phospholipids
These strengthen the plasma membrane
cholesterol molecules
These perform functions on the plasma membrane’s outer surface, providing energy and acting as a platform for cellular recognition
glycolipids (when these start breaking down it can lead to a lot of autoimmune diseases)
The membrane proteins include?
integral proteins & peripheral proteins
Many integral membrane proteins are _____, proteins with carbohydrate groups attached to the ends that pro- trude into the extracellular fluid.
glycoproteins
These proteins are located on the inner and outer surfaces of the phospholipid bilayer; the carbohydrate portions of the glycolipids and glycoproteins form a cell surface coat called the glycocalyx
peripheral proteins
Most integral membrane proteins are _____, which means that they span the entire lipid bilayer and protrude into both the cytosol and extracellular fluid.
transmembrane proteins
_____ proteins extend into or through the lipid bilayer and are firmly embedded in it.
Integral proteins
_____ proteins are not as firmly embedded in the membrane and are attached to membrane lipids or integral proteins at the inner or outer surface of the membrane.
peripheral proteins
The carbohydrate portions of glycolipids and glycoproteins form an extensive sugary coat called the ______, which has a number of functions.
glycocalyx
The _____ composition acts like a molecular “signature” that enables cells to recognize one another. (acts as a tag/identifier)
glycocalyx
The ____ enables cells to adhere to one another in some tissues, and it protects cells from being digested by enzymes in the extracellular fluid (this second action makes red blood cells slippery as they flow through narrow blood vessels)
glycocalyx
An atom that has lost or gained an electron is an ____.
ion
Proteins that catalyze specific chemical reactions at the inside or outside of the cell.
enzymes
Proteins that act as cellular recognition sites.
receptors
Holes formed by proteins through which specific ions, such as potassium ions (K+), can flow through to gain entry or leave the cell.
ion channels
Proteins that selectively move a polar substance or ion from one side of the membrane to the other.
carriers or transporters
Proteins that anchor the plasma membrane of neighboring cells to one another or to protein filaments inside and outside the cell.
linkers
Membrane glycoproteins and glycolipids often serve as _______, enabling a cell to (1) recognize other cells of the same kind during tissue formation or (2) recognize and respond to potentially dangerous foreign cells.
identity markers
Substances move across the plasma membrane in 3 ways. Name them.
passive processes, active processes, vesicular transport
When substances move across the plasma membrane, due to their own kinetic energy, down a concentration gradient (from high to low), this is known as _______
passive processes
A passive process by which substances move down a concentration gradient without any aid provided by membrane components
diffusion (especially movement of gaseous molecules, i.e. heat, perfume, dropping dye into water) (body examples: O2 from lungs to blood, CO2 from cells to lungs, O2 between blood and tissues) (diffusion is mostly nonpolar - goes right through)
A passive process in which water molecules diffuse down their concentration gradient through membrane channels and between neighboring phospholipids (movement of water)
osmosis
_______ is mostly nonpolar, with substances going right through the membrane.
diffusion
A passive process in which substances move down a concentration gradient with the aid of a membrane transporter (carrier) protein
facilitated diffusion
_______ is the passive process that brings most of the polar substances into your cells
facilitated diffusion
______ depends on the solute/soluble concentration. (you have lots of different solutes in your blood)
osmosis
Name the 2 differences of facilitated diffusion from diffusion
(1) carrier protein involved, and (2) involves polar substances
Fluid outside body cells.
extracellular fluid (ECF)