Flashcards in Cell Structure Deck (66)
How could you describe the cell as a system?
A system of membrane bound compartments each with a unique biochemical environment
What does the phospholipid bilayer consist of?
A polar hydrophilic head and a non polar hydrophobic tail
What does amphipathic mean?
Contains a hydrophobic and hydrophilic side
What percentage of the phospholipid bilayer is made up of proteins?
What are the three types of proteins?
Intrinsic, peripheral and transmembrane
Why does the EM of a bilayer show it as a trilaminar layer?
The outer edges are electron dense due to the hydrophilic head of inner layer and lipid tails of each layer but the central is electron lucent
What does the nucleus contain?
DNA and protein called nucleoprotein
What percentage of the nucleus is DNA?
What types of nucleoprotein are there?
Histone proteins and non-histone proteins such as RNA
The nucleus is said to be heterogeneous, why?
It has electron dense and electron lucent areas
What is the electron dense area in the nucleus?
Inactive coiled chromatin found in irregular clumps
What is the electron lucent area in the nucleus?
Euchromatin - DNA active in RNA synthesis
Cells that are involved in highly active protein synthesis are able to be distinguished by staining due to...
A very dense nucleoli is present
The ribosomes and ribosomal RNA are constructed in the
Once the ribosomes and ribosomal RNA have been constructed where are they transported to?
In protein synthesis, what is transcription?
The DNA template of a particular protein is copied to form RNA
mRNA has _____ spliced out. Fill the gap
The mRNA is translated into a protein at which site?
What is an intron?
A segment of a DNA or RNA molecule which does not code for proteins and interrupts the sequence of genes
Describe the general structure of the rough endoplasmic reticulum
A system of flattened tubules covered with ribosomes
What is the main function of the rough endoplasmic reticulum?
To export proteins
What continues on with the rough endoplasmic reticulum?
The smooth ER
What is the difference between RER and SER?
The smooth endoplasmic reticulum has no ribosomes
What is the main function of the smooth endoplasmic reticulum?
Synthesis of lipids and membranes; membrane repair
Give a brief description of the golgi
Stacked membrane bound cisternae
What is a cisternae in the golgi?
refers to a flattened membrane disk that makes up the Golgi apparatus
What is the main function of the golgi?
Glycosylation of proteins and package of proteins into secretory granules
What is the main function of the mitochondria?
The site of energy production by oxidative phosphorylation
What are the four compartments of the mitochondria?
The outer membrane
the inner membrane
the mitochondrial matrix
the inner membrane space