Lecture 1 Flashcards
What is the study of tissues, cells and subcellular components in a biological context?
Microscopy
What is the isolation of subcellular organelles and the components that make them up?
Centrifugation Chromatography.
What are two ways of analysing biological macromolecules such as proteins and DNA?
Gel electrophoresis
Mass-spectrometry
What is the smallest unit of life?
Cells.
What are bacteriophages?
Small viruses that infect & kill bacteria
What are the model cell systems for:
A) Prokaryotes
B) Lower Eukaryotes
C) Higher Eukaryotes
A) E.Coli
B)yeast - S. cerevisiae
C)Human tissue culture cells - HeLa cells
Describe the different properties expressed by fibroblasts, muscle cells and epithelial cells.
Many cultured mammalian cells show differentiated properties that reflect their origin: fibroblast secrete collagen; muscle cells fuse to form muscle fibres and epithelial cells join to form large sheet.
Zebrafish are useful for the study of what?
Vertebrate development
Drosphophila melogaster are useful for the study of what?
(fruit fly)- classical genetics
Caenorhabditis elegans are useful for the study of what?
(nematode worm) genome sequencing
What is the role of Peroxisomes?
Peroxisomes break down fatty acids, alcohol & toxins. Defects in making new peroxisomes can lead to diseases such as Zellweger syndrome = imbalance in lipid metabolism
What is the role of the cytosol?
Typically largest single compartment in the cell and site of many fundamental cellular processes:
- Protein synthesis & degradation
- Intermediary metabolism
What is the role of the nucleus?
- Information store
- Surrounded by nuclear envelope = double membrane
- Contains cellular DNA as chromosomes
- Ribosomal RNA transcribed & ribosomal subunits are assembled
What is the role of the chromosomes?
Chromosome structure changes during the cell cycle when they undergo condensation & decondensation
-Progress towards cell division
What is the role of the mitochondria?
-Inner membrane extensively folded – increased surface area for cellular respiration
-Site of oxidative phosphorylation
Generate ATP = “energy”
-Mitochondria can form complex networks in the cell
What is the role of the chloroplasts?
-In Plants & Algae
Site of photosynthesis = harvesting energy from sunlight.
What is the role of endoplasmic reticulum?
-Irregular maze of interconnected spaces enclosed by a single membrane. Entry point to secretory pathway
-Makes: secretory & membrane proteins + lipids
-Rough endoplasmic reticulum bound to ribosomes
-smooth ER- abundant in human cells active in lipid metabolism and in liver for detoxification of lipid soluble compounds
Sarcoplasmic reticulum-ER derived Ca2+ store in muscle cells: important role during muscle contraction
What is the role of the Golgi?
- Appearance of flattened sacs/discs
- Receives proteins and lipids as cargo from ER
- Cargo transits Golgi to plasma membrane
- Modification of cargo e.g. glycosylation & sorting of cargo to correct location
What is the endomembrane composed of?
Nuclear envelope, ER and Golgi thought to have evolved from plasma membrane = all part of so called endomembrane.
Most synthesis occurs in the..
-cytosol
What is the cytoskeleton composed of?
-Protein filaments such as Actin filament, Microtubules, filaments and Intermediate filaments
-often anchored to the plasma membrane
-Enable directed movement
-Actin- thinnest: movement
-Intermediate filaments: mechanical strength
-Microtubules- thickest: chromosome segregation
(during cell division)
What is cystic fibrosis most commonly caused by?
- most commonly caused by a defect in protein trafficking
- the channel protein is made but it is not delivered to the correct subcellular location.
What is a key factor that causes Alzheimers disease?
- an imbalance in protein processing is one key element
- Results in toxic protein aggregates
Describe what causes tumour formations/cancer
-Uncontrolled cell division
-Invasive character - grow
in the wrong place
-Mutations in the Ras protein prevent it being turned off leading to uncontrolled cell proliferation. 30% of human cancers contain such activating mutations in a Ras gene.
