Organelles Flashcards
What is chromatin?
Genetic material made up of DNA and proteins
What are the 2 types of chromatin?
Heterochromatin and Euchromatin
What type of chromatin is used for gene expression and why?
Euchromatin as the DNA is not tightly wound so it is easy for transcription to occur
Why can’t heterochromatin be involved in gene expression?
The DNA is tightly wrapped around proteins to form solenoids
What are the features of a prokaryotic cell?
No nucleus, cell wall, lacks most organelles, reactions take place in one compartment as there are no internal membranes
What are the functions of the plasmalemma? (5)
Allows for endocytosis and exocytosis Intercellular adhesion Signal transduction Recognition Selective permeability
What are the 2 faces of the Golgi called?
The Formed/Cis face (where proteins are received) and the Budding/Trans face (where proteins are secreted)
What is the function of the Golgi?
Modifies, sorts and packages proteins
What are lysosomes?
Vesicles generated by the Golgi containing hydrolytic enzymes
What is the cell coat of lysosomes made up of?
Polysaccharides and oligosaccharides which stop the lysosome digesting everything
What is the cell coat of a lysosome called?
Glycocalyx
What are peroxisomes?
Vesicles that detoxify compounds using catalase to oxidise toxic molecules
Where are peroxisomes most commonly found?
Liver and Kidney
What are the 3 types of filaments in the cytoskeleton?
Actin filaments, intermediate filaments and microtubules
What are microtubules made up of?
Tubulin
Where are microtubules found?
Where structures move e.g. Cilia, flagella and mitotic spindle
Which is the biggest filament in the cytoskeleton?
Microtubules
What is the mitochondria the site of?
ATP/energy production
From whom do you inherit your mitochondria?
Mother
What do mitochondria contain?
They’re own genome, enzymes for oxidative reaction and ribosomes
What is a secondary lysosome?
A lysosome that has already fused with a bacteria and contains its residue
What is the function of the SER?
Lipid production
What is the function of the RER?
The ribosome on the outside is where mRNA is translated.
What is the difference in shape between the RER and the SER?
The RER compromises of flat cisterna whereas the SER is tubular not flat
What is an amphipathic molecule?
One which has polar and non polar parts
What is the structure of a phospholipid molecule?
Polar, hydrophilic head and a non polar, hydrophobic fatty acid tail
Why is it useful for eucaryotic cells to be compartmentalised?
So that reactions don’t interfere with each other meaning that many reactions can occur
What is the hydrophilic part of a phospholipid molecule and what is the hydrophobic part?
Hydrophilic=polar head
Hydrophobic = nonpolar, fatty acid tail
What is the word that means lipid production?
Steriodogenesis
What does constitutive secretion mean?
The proteins are constantly released
Why are lysosomes acidic on the inside?
As they contain many hydrolytic enzymes
How could you tell the difference between a TEM of a lysosome and a peroxisome?
Peroxisomes are darker
What features do steroidogenic cells have?
Lots of SER to produce steroids
What is the nucleolus?
It is made up of 5 uncondensed chromosomes forming a circular area of heterochromatin that contains sequences of ribosomal DNA
