topic 2 Flashcards
how does cholesterol in the cell membrane increase stabiloty
it reduce fkuidity
compare davidson danieli with fluid mosaic omdel (4)
david, shows that thee are two protein layers with a phospholipid bilayer in the middle whle in fluid mosaic the phospholipid layer has proteins in the layer itself
both sturcutress show presence of proteins and phospholipids
in fluid mosaic, there r diff types of protein that the sturucture doesnt show like intergral protiens, channel proteins
fluid mosaic shows cholesterol but david doesnt
wt protein is needed in cell memebrane for active transport
carrier protein
define endocytosis
endocytosis - movement of large molecules into cels thru vesicle formation. the fluid nature of the cell membrane makes it possible to form vesicles
define exocytosis
movement of large molecules out of the cells thru fusion of vesicles to the membrane
define faciliated diffusion
net movement of prticles from a region of higher to lower conc down a concentration withotu the use of energy with the help of proteins liek channel proteins or carrier proteins
define isotonic, hypertonic and hypotonic
Isotonic – The solution has the same solute concentration as the cell.
Hyypertonic – The solution has a higher solute concentration than the cell.
Hypotonic – The solution has a lower solute concentration than the cell.
wt is ATPase needed for
the enzyme catalyused the hydrolisis of ATIP by breaking one bond and forming two more. this provides energy needed to move carrier systems in the membrane or to release the transported substances
5 adaptations for effective gas exchnage
large surface area
thing layers
rich blood supply
moist surfaces cuz diffusion takes place with the gases in solution
permeable surfaces that allow free passage of respiratory gases
ficks law equation
rate of diffusion = SA x diff in concc/thickness
define breathing/ventilation
moving of air between the lungs and external environment
wt r anabolic and catabolic reactions
anabolic- build of new chemicals
catabolic reacitions - breaking down of susbtantaces
wt r the 3 parts of a nucleotide
5-carbon pentose sugar
a nitrogen containing base
a phosphate grp
diff between purine and pyrimidine
purine has 2 nitrogen containing rings
pyrimidine has only one
ex for purines and pyrimidines.
purine - adenine, guanine
pyrimidine - cytosisne, thymine, uracil
2 functions of mononucleotides
provide building blocks to make chromosomes
provide energy in the form of ATP
diff between dna and rna
dna - double standed
rna - single stranded
dna - has deoxyribose sugar
rna - has ribose sugar
dna - has A T G C grps
rna - has A U C G grps
wt happens in conservative replication
the original DNA stays intact , and a completely new copy is made
wt happens in semiconservative replication
each new DNA molecule has one old strand and one new strand. The DNA unzips, and new strands form by matching bases.
wt does dna helicase, dna polymerase and dna ligase do duirng dna replication
dna helicase - unzips the 2 strands of the dna
dna polymerase - line up the new nucleotides along the dna template strands
dna ligase - catalyses the formation of the phosphodiester bonds between the new nucleotides
define gene
a small section of a chromoseom. a sequence of deoxyribonucleotides
define genetic code
its a triplet code where each codon codes for one amino acid. it is a degenerate code, so it has extra codes containig info than needed.
3 main functions of rna in protein synthesis
carries the instructions for a polypeptide from the DNA in the nucleus to the rhibosomes
picks up specidic amino acids from the protoplasm and carries them to rhibosomes
males up the bulk of the rhibosomes
