UNIT 3.1: THE CELL + CENTRAL DOGMA Flashcards
3 basic components of a nucletodie
Nitrogenous base
Pentose sugar
Phosphate group
Adenine and Guanine are __
Purine bases
Thymine and Cytosine are __
Pyrimidine bases
Pentose sugar + Nitrogen base
Nucleoside
Phosphate group + Pentose sugar + Nitrogen base
Nucleotide
Demonstrated how the 3 components are physically assembled to form DNA
Watson and Crick
DNA is like a twisted ladder with chemical bonds as it runs
Double helix model
Nucleotides are joined to form a ___
Polynucleotide chains
Covalent bond that links adjacent nucleotides
Phosphodiester bond
5’ is the ___ group of the new nucleotide and is linked to the free 3’ __ group of the existing nucleotide
Phosphate
OH
Having opposite orientations
Antiparallel
Important for the attachment of DNA binding proteins involved in replication and transcription
Major and minor grooves
Enumerate the central dogma
Replication
Transcription
Translation
Important in duplicating the DNA so that there will be sister chromatids at anaphase stage at the end of cytokinesis
Replication
DNA replication is ___ because each separated strand serve as template for the synthesis of a complementary strand
Semiconservative
Major steps of replication
Initiation
Elongation
Termination
Unwinding of the double stranded DNA
Initiation
DNA synthesis
Elongation
Rewinding of the double helix
Termination
Unwinds the two DNA strands at the replication fork
Helicase
Stabilize ssDNA as it forms so it will not anneal to reform the double helix
Single-strand DNA binding proteins (SSB)
Releases the tension ahead of the replication fork caused by the unwinding of the DNA helix
DNA Gyrase
The DNA Gyrase releases a the tension and causes a ____ supercoil
positive
The replication bubble is more common on ___ (eukaryote or prokaryote) because their DNA is ___
Prokaryote
Circular
The SSB stabilizes the ssDNA at the ___
Replication fork
Short fragments produced during the discontinuous synthesis
Okazaki fragments
The process by which an RNA sequence is formed from a DNA template
Transcription
Used for RNA synthesis and serves as the template
Template strand
The template strand is also known as ___
Antisense strand
Has the same sequence as the RNA produced, with exception of U replacing T
Coding strand
The non-template strand
Coding strand
The coding strand is also known as ___
Sense strand
Type of RNA produced by the transcription process
mRNA
The RNA polymerase enzyme that binds to a promoter site on the DNA
RNA polymerase II
Pulls a portion of the DNA strands apart from each other and exposes unattached DNA bases during the transcription
RNA polymerase
The RNA sequence is synthesized in ___ direction
5’ to 3’
Transcription continues until a group of bases called ___ is reached
Termination sequence
Processes of post-transcription modification
Splicing
Capping
Polyadenylation
Identify the post-transcription modification process:
Introns in the precursor mRNA are excised, and the exons are spliced together to form a shorter mature mRNA
Splicing
Identify the post-transcription modification process:
5’ end of RNA is ___ by the addition of a methylated guanin nucleotide
Capping
Capped
Identify the post-transcription modification process:
3’ end acquires a poly (A) tail that contains approximately ___ adenine residues)
Polyadenylation
200
The process in which mRNA provides a template for the synthesis of a protein
Translation
Carries code for protein synthesis
mRNA
Component essential for structural support and catalytic activity
rRNA
Adaptor molecule that provides physical and informational link between mRNA and the polypeptide being synthesized
tRNA
Site of protein synthesis
Ribosomes
A subunit of ribosome which is the decoding site
Small subunit
A subunit of ribosome that mediates interaction between mRNA and tRNA
Small subunit
A subunit of ribosome which is the active site
Large subunit
A subunit of ribosome which catalyzes peptide bond formation
Large subunit
In the translation process, the ribosome finds the initiation site on the ___
mRNA sequence
Start codon
AUG (for methionine)
Binds the tRNA to its surface so that base pairing can occur between tRNA and mRNA
Ribosome
The ribosome moves along the mRNA codon by codon in the ___direction
5’ to 3’
An amino acid is translated by the interaction of ___ and ___
mRNA
tRNA
An enzyme that catalyzes the covalent peptide bonds between adjacent amino acids
Peptidyl transferase
The ___ provides the peptidyl transferase
Ribosome
Identify the protein structure:
Linear sequence of amino acids
Primary
Identify the protein structure:
Local folded proteins that occur inside a polypeptide due to atom interactions
Secondary
Identify the protein structure:
alpha-helix and beta-pleated
Secondary
Identify the protein structure:
3D framework or the polypeptide, due to interactions between the R groups of the AA sequence of the protein
Tertiary
Identify the protein structure:
Hydrophobic interactions, H bonds, sulfur bridgers
Tertiary
Identify the protein structure:
Association of two or more polypeptides into multi-subunit complex
Quaternary
Identify the protein structure:
Assembly of individual polypeptides into a larger functional cluster
Quaternary
Identify the type of protein by function:
catalyze covalent bond breakage or formation
Enzyme
Identify the type of protein by function:
Speeds up chemical reactions
Enzyme
Identify the type of protein by function:
Provide mechanical support to cells and tissues
Structural
Identify the type of protein by function:
Serves as antibodies that protect the body from antigens
Protective
Identify the type of protein by function:
Serves as coagulation factor
Protective
Identify the type of protein by function:
Bind to DNA to switch the gene on or off
Regulatory
Identify the type of protein by function:
Carry extracellular signals from cell to cell
Nerve impulse transmission (Hormones)
Identify the type of protein by function:
Carry small molecules or ions
Transport
Represents a self-regulated sequence of events that controls cell growth and cell division
Cell Cycle
Identify the organelle:
non-membrane bound organelles that are responsible for the synthesis of protein
Ribosomes
rRNA are synthesized in the ___
Nucleolus
Component of ribosome
Protein + rRNA
Ribosomes are attached to the ___
RER
T/F: ribosomes may be free floating in the cytoplasm but not attached in the perinuclear membrane
F (they can be both)
Identify the organelle:
Responsible for glucose and lipid synthesis
SER
Identify the organelle:
Site for post-transcriptional modification
Golgi body
Identify the organelle:
Site of oxidative phosphorylation
Mitochondria
Identify the organelle:
Provides energy to the cell by producing ATPs
Mitochondria
Identify the organelle:
Responsible for cell division
Centrosome
Identify the organelle:
Complex structure that contains two barrel-shaped centrioles
Centrosome
A prominent regulator of cell division
Actin
Plays essential role during centrosome separation, chromosome movements, spindle organization, spindle positioning, and mitotic checkpoint silencing
Dynein
Identify the organelle:
Produces hydrogen peroxide for cell clean up
Peroxisome
Identify the organelle:
Also known as microbodies
Peroxisome
Chromosome is a condensed ___
Chromatin
Threadlike strands of nuclear DNA with proteins
Chromosome
Protein in the nuclear DNA
Histones