Lesson 8 Flashcards
Protein making
-DNA strands unwind to expose bases, this attracts free floating nucleotides which produce RNA the RNA then detaches and carries the code outside of the cell for transcription
Transcription
-Early phase of protein synthesis in which the DNA strands unwind and a complementary strand of messenger RNA is produced
Translation
-later phase of protein synthesis in which the messenger RNA travels from the nucleus to the ER
-MRNA is translated into a particular sequence off amino acids to form a protein
Amino acids
-Building blocks that form polypeptides and proteins
-fundemental for protein synthesis
polypeptide chain
-a series of amino acids
What do proteins do
-regulate the flow of substances across the membrane
-can be exported from cell to cell
-can act as a messenger molecule
Golgi bodies
-package proteins in membranes and give them a label indicating where they go
microtubules
-Transport the vesicles to their destination inside or outside of the cell
what changes the shape of proteins
-can change shape when other chemicals bond to them or in response to electrical charge
-shape change resembles the lock on a door
channel membrane crossing
ions can cross a cell membrane through the appropriate shaped channel
Gate membrane crossing
- a gate channel changes shape to allow passage of substances when gates are open
Pump membrane crossing
-a pump transporter changes shape to carry substances across a cell membrane
Mendelian genetics
-studies on how genes influence our traits
-named after Gregor Mendel
autosomes
-pairs 1 through 22 of the chromosome pairs in the nucleus, contains genes that contribute most to our physical appearance and behaviour functions
sex chromosomes
-contribute to our physical and behavioural sexual characteristics
complete dominance
-only the dominant alleles trait is expressed in the phenotype
Incomplete dominance
-the phenotypic expression of the dominant alleles trait is only partial
codominance
-the traits of both alleles of a gene pair are expressed completely in the phenotype
How do genetic mutations occur
-errors can arise in the nucleotide sequence when reproductive cells make gene copies
-mutations can be very small
genetic disorders
-results from an aberration in part of chromosome rather than a single defective allele
Down syndrome
-caused by having an extra chromosome 21 so they have 3 chromosome 21s instead of 2
-normally the mother passes on 2 chromosome 21s and the dad passes 1
Selective breeding
-mating animals that have good traits together so that their offspring also have that trait, for example breeding fat cows together to get bigger cows.
Cloning
-producing an offspring that is genetically identical to another animal.
-clones can be use to preserve valuable traits, to study the influence of heredity and enviorment or to produce new tissue or organs for transplant to the donor
Transgenic techinique
-introducing genes into an embryo or removing genes from an embryo