Molecular Cell Biology Flashcards
(33 cards)
Biomarkers
A naturally occurring molecule, gene, or characteristic by which a particular pathological or physiological process or disease, can be identified
C-Reactive Protein (CRP)
- Measure of inflammation
- CRP is a general marker so isn’t useful for precise diagnosis
Anti Citrillunated Peptide Antibody
- Used to help diagnose rheumatoid arthritis
- ACPA is more definitive 95% of people who have it also have RA
Disease Specific Biomarker
- Uses
- Diagnose disease
- Monitor disease progression
- Predict response of treatment
- Prognostic - E.g. breast cancer and BRCA1 gene mutation
- Low risk
- High risk
Define Translational Research w Example
Translational medicine is an effort to build on basic scientific research to create new therapies, medical procedures, or diagnostics.
*Example: Ab block of TNF was thought to treat rheumatoid arthritis.
Define Stratified Medicine. 4 categories, explain use in practice.
Making sure you’re treating the patient with the correct medicines. based on genetic and epigenetic makeup.
Benefit + No Toxicity
Benefit + Toxicity
No Benefit + No Toxicity
No Benefit + Toxicity
- Depends on severity of disease and if benefits outweigh the risks, e.g. if indigestion tablets work but causes adverse reaction then it isn’t feasible.
Example of Stratified Medicine in Practice.
Breast cancer has many different biomarkers which can affect treatment.
- Estrogen receptor ER+ patients are treated with Tamoxifen
- HER2+ patients can be given herceptin
Cetuximab and K-RAS mutation
Cetuximab inhibits K-RAS which stops enzyme cascade leading to proliferation. A mutation in K-RAS allows it to evade the effects of the drug. Drug only works if the K-RAS gene is normal.
Personalised Medicine
Medical care in which the treatment is customised for an individual patient
CAR T-cell therapy mechanism
T-cells isolated via leukophoresis from patient with cancer. Introduce a gene into a lentivirus which causes it to present the antigen which is present on the cancer. they then expand T-cells up which respond to the cancer then it is administered to the patient. the T-cells go round and fight the cancer in the body
Gene Therapy: SCID.
- What is SCID?
- Why would it work?
- Treatment (Old and New)
Severe combined immunodeficiency.
-Rare inherited diseases where children are born with defective immune systems due to a gene mutation.
-It would work because it is a monogenetic defect so it is easier to correct.
-Old: Bone marrow transplants from donor, risk of rejection and latent viruses
New: take stem cells from Bone marrow and GM them using a virus then reimplant them
Differences between eukaryotic & prokaryotic cells
Euk/Prok size - 5microm/1-5microm nucleus - Yes/No Organelles - Yes/No Chromatin - Yes/No Cell wall - No(except plants)/ Yes Chloroplasts - Plants/ Some
Features of an animal cell with function
Nucleus - contains DNA in the form of chromatin.
Nucleolus - makes rRNA within the nucleus.
Mitochondria - makes energy
Endoplasmic reticulum - RER has ribosomes for protein synthesis
Golgi - involved in secretion
Intermediate Filament - involved in structure
Microtubule - Structure of the cell, part of cytoskeleton originate from centrosomes which are involved in cell division
Cell Membrane features
- Phospholipids
- Cholesterol
- Membrane Proteins
- Glycolipids (binding sites and cell specificity)
Functions of the membrane
- Define the boundary of the cell
- Regulate transport of solutes
- Mediate cell communication
What are Phospholipids made of
- Polar head
- Non polar hydrophobic tail
-Phosphate forms the head which can be attached to an R group.
the bend in the tail is important for its function in the membrane.
What affects the fluidity of the membrane?
- % of cholesterol
- How many bends in the hydrophobic tails
Permeability of the membrane
- Permeable
- Impermeable
- Semi-permeable
Permeable
- Gases
- Small uncharged polar molecules (Ethanol)
Semi-permeable
- Water
- Urea
Impermeable
- Large uncharged polar molecules (glucose)
- Ions
- Charged polar molecules (protein, aa, ATP)
Types of integral membrane proteins
- Transporters
- Anchors
- Receptors
- Enzyme
Types of Transporters and functions
Channel proteins - passive diffusion down conc gradient
Transporter mediated - for larger molecules
Active transport - uses energy to pump against conc gradient
Mitochondria - function and structure
- Function
to produce energy for the cell via ATP generation. - Structure
Permeable outer membrane
Less permeable inner membrane folded into cristae
Inside the inner membrane is the Matrix
How does the mitochondria make ATP?
- Pump is driving H+ into the intermembrane space forming a strong proton motive force which then drive the ATP synthase which is the turbine generating ATP from ADP and Phosphate
Golgi Apparatus function
modification, packaging and sorting proteins ready for secretion or for another organelle.
Lysosomes and peroxisomes
what are they and what’s their function?
Lysosomes
-Small irregular cytoplasmic vesicles
-Packed with degradative enzymes
-Principal sites of intracellular digestion
=
Peroxisomes
-Small cytoplasmic vesicles
-Contained environment for reactive H2O2 generation
-The main function of the oxidation reactions is the breakdown of fatty acids
-Detoxify toxic substances such as ethanol (via catalase)
