Medical Cell Biology and Genetics (MCBG) Flashcards
What is heterochromatin and does it show as light or dark in em?
DNA stored as solenoids.
Dark.
What is euchromatin and does it show up as light or dark in em?
DNA stored as beads on a string.
Light.
Are euchromatin or heterochromatin genes expressed?
Euchromatin
What is the limit of resolution?
The minimum distance at which two objects can be distinguished.
How do prokaryotic cells differ from eukaryotic cells?
Prokaryotes have no nucleus, they have a cell wall and no membrane bound organelles (all biochemical processes occur in the same compartment).
What are the parts of a phospholipid?
Hydrophilic head- choline, phosphate, glycerol
Hydrophobic tail- 2 fatty acids
What does amphipathic man?
Both hydrophilic and hydrophobic
What is the glycocalyx?
Cell sugar coat on outside of plasma membrane
What is the fluid mosaic model?
Phospholipid bilayer
Proteins embedded in the bilayer
What are the functions of the plasmalemma?
Selective permeability Transport of materials along cell surface Endo/exocytosis Intercellular adhesion/recognition Signal transduction
Function of RER
Protein synthesis
Function of SER
Lipid synthesis and transport
Ovary/testis/adrenal gland- steroidogenesis
Where is the destination of the product of free ribosomes and ribosomes on the RER?
Free-cytoplasm
RER-for export
Which sides are the cis and trans faces of the Golgi body?
Cis-side closest to RER
Trans-opposite side
Functions of Golgi body?
Modify, sort , concentrate and package proteins into vesicles
What are the types of secretion?
Signal-mediated diversion to lysosomes
Constitutive secretion
Signal-mediated diversion to secretory vesicles for regulated secretion
What is the difference between primary and secondary lysosomes?
Secondary lysosomes have already fused with a bacterium and broken it down. Bacterial matter is left inside.
What makes lysosomes?
Golgi apparatus
What do lysosomes do?
Fuse with material requiring digestion
What do peroxisomes do?
Detoxify molecules in the liver/kidney including alcohol, phenols, formed acid and formaldehyde
How often do mitochondria divide?
Every time the cell divides
How are actin microfilaments distributed in the cell?
Around the edge and in microvilli
How are intermediate filaments distributed in the cell?
Evenly around the cell (not microvilli)
How are microtubules distributed in the cell?
Branching out from nucleus (not microvilli)
How are microtubules arranged in a cilium/flagellum?
9+2 arrangement
What type of helix is DNA?
Right-handed alpha helix
What is the major groove?
Large gap in side of helix
How is DNA packaged?
DNA is wrapped around histones with linker DNA connecting each of these. 8 histones make up one nucleosome. These beads on a string are then packaged into solenoids.
What are genes?
They carry the code for proteins
What is the genome?
Entire DNA sequence
What is a nucleoside?
Base and sugar
What is a nucleotide?
Base, sugar and phosphate
What is the difference between ribose and 2-deoxyribose?
There is no O on the second carbon
Why is DNA negatively charged?
The phosphate group is negatively charged
Which bases are purines?
Adenine and guanine
Which bases are pyramidines?
Cytosine, uracil, thymine
What type of polarity does DNA have?
5’ to3’
Why is DNA 5’ to 3’?
A phosphate is bonded to both the 3rd and 5th carbon
How many hydrogen bonds form between G andC?
3
How many bonds form between A and T?
2
What is heterochrimatin and does it show as light or dark in em?
DNA stored as solenoids.
Dark.
What is euchromatin and does it show up as light or dark in em?
DNA stored as beads on a string.
Light.
Are euchromatin or heterochromatin genes expressed?
Euchromatin
What is the limit of resolution?
The minimum distance at which two objects can be distinguished.
How do prokaryotic cells differ from eukaryotic cells?
Prokaryotes have no nucleus, they have a cell membrane and no membrane bound organelles (all biochemical processes occur in the same compartment).
What are the parts of a phospholipid?
Hydrophilic head- choline, phosphate, glycerol
Hydrophobic tail- 2 fatty acids
What does amphipathic man?
Both hydrophilic and hydrophobic
What is the glycocalyx?
Cell sugar coat on outside of plasma membrane
What is the fluid mosaic model?
Phospholipid bilayer
Proteins embedded in the bilayer
What are the functions of the plasmalemma?
Selective permeability Transport of materials along cell surface Endo/exocytosis Intercellular adhesion/recognition Signal transduction
Function of RER
Protein synthesis
Function of SER
Lipid synthesis and transport
Ovary/testis/adrenal gland- steroidogenesis
Where is the destination of the product of free ribosomes and ribosomes on the RER?
Free-cytoplasm
RER-for export
Which sides are the cis and trans faces of the Golgi body?
Cis-side closest to RER
Trans-opposite side