Biology & Immunology Flashcards
4 Bases of DNA
Adenine
Thymine
Guanine
Cytosine
Transcription
Process for DNA to RNA via RNA polymerase
Translation
Process from mRNA to strand of amino acids which forms a protein
Essential Amino Acids
Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine Arginine* Cysteine* Glutamine* Pyrrolysine* Proline* Selenocysteine* Serine* Tyrosine*
Which cells don’t proliferate after birth?
Nerve cells
Muscle cells
Cardiac cells
Which cells are capable of self-renewal?
Stem cells
2 Types of Growth Factors
Stimulate cell division
Inhibit cell division
Cell Cycle Phases
G0 G1 S G2 M
Define G0 Phase
A resting phase where the cell has left the cycle & has stopped dividing
Define G1 Phase
Cells increase in size
What is the G1 checkpoint?
Control mechanism ensures that everything is ready for DNA synthesis
Define S Phase
DNA replication occurs during this phase
Define G2 Phase
Gap between DNA synthesis & mitosis
Cell continues to grow
What is the G2 checkpoint?
Control mechanism ensures that everything is ready to enter the M phase & divide
Define M
Cell growth stops at this stage & cellular energy is focused on the orderly division into two daughter cells
What is the metaphase checkpoint?
Ensures that the cell is ready to complete cell division
2 Categories of Cancer Genes
Dominant: proto-oncoggenes
Recessive: tumor suppressor
Define Gain of Function Mutations
Altered or unregulated activity of a “photo-oncogene” leads to tumorigenesis
Define Loss of Function Mutations
Loss of activity of tumor suppressors results in unregulated pathways and tumorigenesis
“Hallmarks of Cancer”
Self-sufficiency in growth signals Insensitivity to anti-growth signals Evading apoptosis Limitless reproductive potential Capacity to invade other tissues Sustained angiogenesis Tissue invasion & metastases Genomic instability
How do cancer cells invade our bodies?
Resisting apoptosis CSCs forming resistant phenotypes Epithelial-mesenchymal transitions Interactions with microenvironment Invadopodia & aquaporins Genetic alterations
Invadopodia
Actin rich membrane protrusion formed by invasive cancer cells (protrude through basement membranes)
Cancer Stages
Stage 0: mucosa level Stage 1: through the submucosa Stage 2: through the muscle layers Stage 3: through the serosa Stage 4: through serosa and spread to other organs