plasma membrane
single phospholipid bilayer
- contains proteins embedded into its bilayers
nuclear membrane
continuous double phospholipid bilayer (inner & outer)
- contains proteins embedded into its bilayers
nucleolus
responsible for ribosomal RNA processing and assembling ribosomal subunits
- site of ribosome assembly
gene
a sequence of DNA—located at a specific locus—with a specific job or function
metabolic pathway
a linked series of biochemical reactions that build up or break down a particular molecule
- product of one reaction is the substrate of the next reaction
locus
location on a chromosome
allele
gene sequence variability, which leads to variations in the gene function
nuclear localization signal (NLS)
a short amino acid sequence that marks a protein for delivery to nucleus
components of a nucleic acid
(1) phosphate group
(2) 5 carbon sugar
(3) nitrogenous base
antiparallel
opposing orientation of nucleic acid strands that are hydrogen bonded to one another
complementary base pairs
pair of bases that only bond to one another
ribozyme
RNA enzyme that act as a catalyst by speeding up a chemical reaction
- contains uracil instead of thymine
genotype
alleles of a gene
- determined by sequence of bases in its DNA
phenotype
physical traits expressed according to a genotype
- product of proteins it produces
central dogma
scheme for information flow in the cell: DNA S RNA S protein
types of transportation through nuclear pores
(1) nuclear export signal (mRNA)
2) nuclear localization signal (lamin
nucleotide structure
1’ - base
2’ - R (DNA or RNA) = OH or H
3’ - OH (polymer)
4’ - connect to 5’
5’ - phosphate
(1B 2R 3OH 45 5P)
purine
class of small, nitrogen-containing, double-ringed bases found in nucleotides - bases: adenine & guanine
*linked juntos by 9 atoms
pyrimidine
class of small, nitrogen-containing, single-ringed bases found in nucleotides - bases: cytosine, thymine OR uracil
*linked juntos by 6 atoms
polymer properties
(1) condensation reaction
(2) phosphodiester bond
(3) sugar-phosphate backbone
(4) 5’ & 3’ ends
(5) primary structure depends on order of nucleotides
primary structure
depends on order of nucleotides
secondary structure
depends on H-bonds
nucleic acid functions in DNA
make up genetic material
nucleic acid functions in RNA
(1) gene expression (mRNA, tRNA, rRNA, siRNA)
(2) ribozymes
(3) ATP & GTP
(4) genetic material in some viruses