Session 1-Basic Cell Structure Flashcards
What is a nucleosome?
Structural unit of eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones
What is heterochromatin?
Chromosome material that stains most deeply when the cell isn’t dividing
Genetically inactive
Tightly coiled
What is euchromatin?
Chromosome material that stains most deeply during mitosis.
Prevalent in cells that are active in transcription of many genes.
Loosely coiled
What is the glycocalyx made up of?
Oligosaccaride and polysaccharide side chains
What are the functions of the plasmalemma? (6)
Selective permeability Transport materials along cell surface Endo and exocytosis Intercellular adhesion Intercellular recognition Signal transduction
What is the function of the Golgi apparatus?
Modify, sort, concentrate and package proteins synthesised on the RER
What are lysosomes?
Generated by the Golgi apparatus and contain many hydrolytic enzymes. They fuse with material requiring digestion.
What do peroxisomes do?
Oxidise number of molecules like alcohol, phenols, formic acid and formaldehyde
What is the function of the mitochondria?
To generate ATP by oxidative phosphorylation
What are the functions of the endoplasmic reticulum?
Lipid and steroid synthesis
Membrane synthesis
What are the functions of the nucleus?
RNA synthesis
DNA synthesis and repair
RNA processing and ribosome assembly
What is the function of ribosomes?
Protein synthesis
What are the functions of cytoplasm?
Fatty acid synthesis
Metabolism of carbs, AA and nucleotides
How can differences in bacterial and mammalian cell structure and function be exploited in medicine?
Antibiotics (eg penicillin) prevents the final cross-linking step of producing peptidoglycan which makes the cell wall of the bacteria. This means that the cell is now fragile and bursts, killing the bacterium.
Define amphipathic
Molecule that has both hydrophobic and hydrophilic parts
How can rapid breathing (hyperventilation) cause an increase in blood pH?
When the body receives more O2 than it needs, the result is known as respiratory alkalosis which causes an increase in blood pH.
What effect would pulmonary obstruction have on blood pH?
Decrease pH - inefficient gas exchange so excess CO2 in blood, making acidic carbonic acid (respiratory acidosis)
What are microtubules?
Long hollow cylinders made of the protein tubulin, found at sites where structures are moved (ie nerve fibres, mitotic spindle, cilia and flagella)
What causes the blistering of skin?
Mutant keratin gene
What are intermediate filaments?
These are common in epithelial cells and form a tough supporting mesh work in the cytoplasm. They can also be found beneath the inner nuclear membrane forming the nuclear lamina
What is the limit of resolution?
Minimum distance at which two objects can be distinguished
Where can the SER be found?
Liver, mammary gland (lipid biosynthesis), ovary, testis and adrenal gland (steroidogenesis)
What does the trans face of the Golgi body do?
Secrete substances
What does the cis face of the Golgi body do?
Form substances
What is the medical name for blistering of skin?
Epidermolysis bullosa
