Topic 2 Flashcards
where is DNA located
Nucleus (cytoplasm if no nuclei)
What does DNA do? (2)
contains genetic code which dictates all inherited characteristics by controlling protein manufacture
Carries genetic info from 1 organism to the next
Gene def
a sequence of BASES on a dna molecule that codes for a sequence of AMINO ACIDS on a POLYPEPTIDE CHAIN
What is DNA
a chain of nucleotides
what are mononucleotides
3 molecules linked together by condensation reactions:
- deoxyribose (5 carbon sugar)
- phosphate group
3 organic base containing nitrogen (variable)
what bond holds together mononucleotides (to make a nucleotide)
PHOSPHODIESTER
Hydrogen bonds are between AT and CG groups
why do bases pair up
A and G have a 2 ring structure; C and T only one ring. Join to form 3 rings to ensure DNA has a uniform width along whole length.
What is the genetic code
sequence of bases in DNA, which tells the cell which amino acids to link together
what is purpose of protein synthesis
transfer DNA through membranes surround it into cytoplasm
where does transcription take place
nucleus
what does degenerate mean in translation
several triplets can code for the same amino acid
what joins amino acids together
a peptide bond
what does mucus in the airways do
traps dust// debris// microorganisms
What does mucus containing less water mean
increased risk of lung infection
less efficient gas exchange
what is osmosis
the passive process of the random, net movement of water molecules from a solution of lower concentration of solute to a solution of higher concentration of solute through a partially permeable membrane (phospholipid bilayer)
what is active transport
the movement of a substance across a membrane fro low to high concentration with energy transfer molecule ATP
Requires specific carrier proteins
when is atp formed
breakdown of energy storage molecules (fats + carbs)
respiration
what is exocytosis
the release of substances from the cell by vesicles fusing with the membrane and releasing its contents
what is endocytosis
substances are taken into the cell by creation of a vesicle on cell surface membrance
what are endocytosis and exocytosis for?
transport of large particles or large quantities of a particular molecule across the cell surface membrane
effect of CF on the digestive system (3)
difficulty maintaining body mass
high metabolic rate
poor appetites
