MCBG Flashcards
What is the rough endoplasmic reticulum ?
The Rough Endoplasmic reticulum is a network of membranes in the cell that are covered in ribosomes, and play a role in protein synthesis
What is the fluid of the cytoplasm called?
The fluid of the cytoplasm is called cytosol and has a pH of 7.2
What are inclusion bodies?
Inclusion bodies are non-metabolically active substances within the cell, such as lipid droplets and metabolites, which do not survive cell division
Main Structure of the plasmalemma?
-Three layers
-2 phosoplipid layers
-Non-polar (hydrophobic) fatty acid tails of phospholipids go into the middle layer
-Polar (hydrophilic) heads located on inner and outer side of the membrane
Function of the peripheral proteins of the plasmalemma?
-Peripheral proteins adsorb so inner and outer side of the membrane
-Involved in cell recognition and interactions
Function of integral proteins of the plasmalemma?
-Integral proteins go through the width of the membrane
-regulate passage and materials and active transport
Principle functions of the plasmalemma?
-Communication through receptors on the outer surface
-Intercellular connectivity
-Barrier between inner/outer cellular compartments
-Selective permeability
Describe the structure of a mitochondrion?
-Outer, sieve-like membrane and inner folded membrane, separated by intermembranous space
-Inner membrane has finger-like folds called cristae
-Space deep within the inner membrane is called the matrix
-Integral proteins on inner/outer membranes provide passage for small molecules
-Matrix has some chromosomes, ribosomes and RNA in order to synthesise a small amount of proteins
What does the number of cristae in a mitochondrion correspond to?
The number of cristae in a mitochondrion corresponds to the energy needs of the cell
Why are mitochondria eosiniophillic?
Mitochondria are stained by eosin due to the high content of mitochondrial DNA
Structure of a ribosome?
-Small, electron dense particles
-Made of RNA and 80 different proteins
-Exist in three different forms
What are the three different forms ribosomes can exist in?
-An isolated particles
-Polyribsome, many ribosomes on an mRNA strand
-Rough endoplasmic reticulum, where ribosomes have adsorbed to endoplasmic reticulum
Which form of ribosomes synthesises cytosolic (free) proteins?
Polyribsomes synthesise cystosolic proteins
Which form of ribosomes synthesises secretory and endoplasmic reticulum proteins?
Rough Endoplasmic Reticulum (ER with ribosomes adsorbed) synthesises secretory and endoplasmic reticulum proteins
Why are ribosomes called basophillic?
Ribosomes are basophillic because they are stained by most basic dyes
