Biochem Final part 2 Flashcards
Micelles
spherical structures containing amphipathic molecules arranged with hydrophobic regions in the interior and hydrophilic head
groups on the exterior (type of hydrophobic interaction)
vesicles
forms spontaneously when a bilayer sheet folds back on itself to form a hollow sphere (type of hydrophobic interaction)
bilayers
a noncovalent heteropolymer of lipid bilayer and associated proteins
- A film two molecules thick that is arranged with its hydrophobic end inward and its hydrophilic end outward.
Integral vs. peripheral membrane proteins
integral: proteins embed in or pass through the membrane
peripheral: proteins are bound to the membrane primarily through noncovalent interactions
Lipid raft
dynamic assemblies of proteins and lipids that float freely within the liquid-disordered bilayer of cellular membranes but can also cluster to form larger, ordered platforms
- type of microdomain
-cholesterol, sphingolipids
Gene
a DNA sequence that contains the base sequence information to code for a gene product, protein, or RNA
Genome
The complete DNA base sequence of an organism
transcriptome
The total RNA transcripts for an organism
proteome
the entire set of proteins synthesized
metabolome
refers to the sum total of low molecular weight metabolites produced by the cell (sugars, nucleotides, amino acids, lipids)
Purine
amine base in DNA (adenine and guanine)
pyrimidine
anime base in DNA (cytosine and thymine)
Point mutation
small single base changes such as transition and transversion mutations.
frameshift mutation
Indels that occur within the coding region that are not divisible by three
Codon
A sequence of three consecutive nucleotides in a DNA or RNA molecule that codes for a specific amino acid
anticodon
a sequence of three nucleotides forming a unit of genetic code in a tRNA molecule, corresponding to a complementary codon in messenger RNA
Chromosome
a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes
nucleosome
-a section of DNA that is wrapped around a core of proteins (inside the nucleus)
-formed by the binding of DNA and histone proteins
chromatin
Each eukaryotic chromosome consists of a single, linear DNA molecule complexed with histone proteins to form nucleosomes ( this complex is called chromatin)
Replication fork
New nucleotides line up on each strand in a complementary manner, A to T / G to C, and two new strands begin to grow from the ends of the bubble
- where DNA replication takes place
Leading vs. lagging strand (Okazaki fragments)
(DNA replication)
Leading Strand: The complement of the original 3’ to 5’ strand is synthesized
continuously in a single piece to give a newly synthesized copy
Lagging strand: complement of the original 5’ to 3’ strand is synthesized discontinuously in small pieces called Okazaki fragments that are subsequently linked by DNA ligases to form the lagging strand
Template/nontemplate strand
The template strand (-) of DNA is antiparallel to the new RNA strand
The non-template strand (+) has the same base sequence as the RNA, except the transcript has U for T
coding/noncoding strand
The DNA strand that contains the gene is the coding strand/ sense strand
The DNA strand that gets transcribed to give RNA is called the noncoding/ antisense strand
sense/antisense strands
the segment within double-stranded DNA that carries the translatable code in the 5′ to 3′ direction
Constitutive genes
routinely transcribed because they code for gene products required for normal cell function
inducible genes
a gene whose expression is either responsive to environmental change or dependent on the position in the cell cycle
repressible genes
those in which the presence of a substance (a co-repressor) in the environment turns off the expression of those genes
