E. Biology and Physiology Flashcards
Where is the site of ATP production in eukaryotic cells?
Mitochondria
Where is the ribosomal RNA located in a eukaryotic cell?
nucleolus
Where are ribosomes making proteins for EXPORT from the cell located in eukaryotic cells?
rER
Where is the site where proteins may be glycosylated in eukaryotic cells?
Golgi apparatus/complex
Where is the location where proteins for transport TO the nucleus are made in eukaryotic cells?
Ribosomes
Where is the site where proteins may be broken down in eukaryotic cells?
Lysosomes
What is extrachromosomal DNA and where is it found in human cells?
DNA that exists outside the main chromosome and acts independently.
Mitochondria
What is cytosol?
Water + inorganic ions and small organic molecules in the cell
What is the cytoplasm?
the cytosol + organelles of the cell, within the cytoplasmic membrane but excludes the nuclues.
How does complexity of structure and function change as we move from viruses to larger cells, e.g. animal cells?
They become more complex
How is the baility to change and evolve affected when a we move from a virus to larger cells. e.g. animal cells
The ability decreases
Where s the lamina in a nucleus and what is its function?
It lines the surface of the inner nuclear membrane and it is a nework of protein fibres which help maintain structural intergrity
Which organelles in animal cells are double menrand?
Nucleus and mitochondria
Explain the structure of chromosomes?
Chromosome
Chromatids joined at the centromere (chromatids are the halves)
=
Chromatin =
Histone proteins wrapped
around DNA strand
What are the different forms of chromatin?
Heterochromatin (tightly packed) AND Euchromatin (loosely packed)
What are functions of euchromatin and heterochromatin
Euchromatin is where gene transcription occurs and heterochromatin is very condensed so no gene transcription occurs here.
What are the rotatory directions by optical rotation of plane polarised light?
- Dextrorotatory (D/clockwise)
- Laevorotatory (L/anticlockwise)
What is the meaning of isoelectric point of an amino acid?
The pH at which the amino acid becomes neutrally charged
How to amino acids usually exist?
As zwitterions
What is a structural motif in proteins?
a common 3D feature which is present in a variety of UNRELATED molecules
What does conformation change mean in terms of proteins?
Change in the 3D structure of a protein
What si prosthetic group in proteins?
The non-amino acid component
What does allosteric mean in terms of proteins?
The binding of a molecule to one part of the protein influences the binding to other regions of the protein
What are the different ways enzymes work?
- Oxidoreductases - Transfer of electrons
- Transferases- Transfer of functional groups between molecules
- Hydrolases- Hydrolysis reactions
- Lyases- Cleavage of bonds, often forming a double bond
- Isomerases- Transfer of groups within a molecule
- Ligases- Bond formation coupled to ATP hydrolysis
What is domain in terms of proteins?
Distinct functional and/or structural regions in a protein, and t often function and fold independently from the rest of the protein.
What do cell membrane proteins do?
used for transportation, scommunication, recognistion and structural support
What are the different types of co-transporter proteins?
uniport-carries a molecule unidirectionally
symport- two molecules simultaneously in the same directon
antiport- 2 moleclues simultaneously in opposite directions (one in and one out)
Factors affecting diffusion
- steepness of concentration gradient
- size or mass of diffusing substance
- SA
- diffusion distane
What are the differences on each side of the membrane which affect transport by diffusion?
Chemical and electrical differences
What is proton motive force (PMF)?
Energy gradient due to more h+ out of the membrane
ABC transporter meaning
ATP Binding Cassette transporter
What are bacterial transport systems?
Translocases
due to the cell wall they do not transport via exo/endo cytosis
What is pinocytosis?
uptake of extra-cellular fluid via small membrane vesicles OR Cell drinking
receptor mediated endocytosis involves the protein…which has been mostly studied for the uptake of cholestrol
Clathrin
What are the two adhesion molecules which allow ceel to sense their enrionment
cadherins and integrins
