Heredity and Society (Lecture 7-11) Flashcards
protein synthesis
DNA to protein
2 steps of protein synthesis
transcription and translation
Transcription
process by which mRNA or RNA strands are made from DNA strands
Translation
the synthesis or making of a protein from mRNA transcript
Proteins
- Composed of amino acids
- about 20 different amino acids
- billions of combinations possible
codons
codes amino acids
Structural
keratin, collagen
hormones
insulin, human growth
body defense
anitbodies
transport
hemoglobin
motion
actin and myosin
enzymes-catyladt
polymerases essential for DNA replications and gene expression
Prions
Protien gone wrong
Prions cause
infectious diseases,
examples, vCreutzfeldt- Jakob
-fatal familia insomnia
-bovine spongiform encephalopathy (BSE) or mad cow disease.
mutation
chnages in the nucleotide sequence or chromosme
types of mutations
Germiline- in germ cells-pass to generations
Somatic occurs in body cells-during replication before mitosis-not inheritable
causes of mutations
spontaneous occurs randomly- no external cause
induced by exposure to mutagens such as radiation or chemicals
Base analogs
structually resemble bases
food persevatives
(nitrates to nitrous acid) may modify the structure of bases and an incorrect base is inserted
pesticides
can insert inside a DNA helix and distort
Cancer inherited susceptibility
Mutant gene in germ cells (predisposition)
Sporadic
(Acquired) 1 or more mutations accumulate spontaneously or by exposure to environmental agents in somatic cells
Most common cause of cancer
Sporadic
Tumor suppressor genes
Suppress or turn off cell division (brakes)
Porto-oncogenes
Stimulates the cell growth -pushes the cell through all the check points
-if mustered, become oncogenes (accelerator)
Oncogenes
Accelerator