Cell Cycle and Molecular Biology Concepts

This set of flashcards covers key concepts in cell biology, genetics, molecular biology, and cellular processes based on the lecture notes.

Cell Cycle Checkpoints

Regulatory points ensuring proper cell division.

Cancer

Disease caused by uncontrolled cell division.

Germ Line Mutation

Mutation passed to future generations; present in whole body.

Somatic Mutation

Mutation during cell division; local effects.

Substitution Mutation

Replacement of one base with another.

Insertion Mutation

Addition of one or more nucleotides.

Deletion Mutation

Removal of one or more nucleotides.

Silent Mutation

No change in amino acid sequence.

Missense Mutation

Change in one amino acid in protein.

Nonsense Mutation

Creates a premature stop codon in protein.

Frameshift Mutation

Disruption of reading frame due to insertions or deletions.

MPF

Maturation promoting factor for G2 checkpoint.

Cyclin

Protein regulating cell cycle progression.

Cyclin-dependent Kinase (Cdk)

Enzyme activated by cyclin for cell cycle control.

Huntington's Disease

Genetic disorder caused by triplet repeat expansion.

Sickle Cell Anaemia

Blood disorder caused by missense mutation.

STOP genes

Genes that inhibit cell cycle progression.

GO genes

Genes that promote cell cycle progression.

Genetic predisposition

Inherited mutations increasing cancer risk.

Acquired mutations

Mutations occurring in individual cells due to carcinogens, UV exposure, etc.

Proto-oncogenes

Normal genes stimulating cell proliferation.

Tumor suppressor genes

Genes regulating and inhibiting cell growth.

Oncogenes

Mutated proto-oncogenes leading to cancer.

Carcinogens

Substances causing cancer through DNA damage.

Eukaryotic Cell Cycle

Series of phases for cell growth and division.

Mitosis

Somatic cell division producing identical daughter cells.

Meiosis

Reproductive division creating genetically diverse gametes.

Interphase

Phase where cell prepares for division.

G1 Phase

Growth phase with active cellular functions.

S Phase

DNA replication occurs, forming sister chromatids.

G2 Phase

Preparation for mitosis, checks DNA synthesis.

Prophase

Chromatin condenses into visible chromosomes.

Metaphase

Chromosomes align at the cell's equatorial plane.

Anaphase

Sister chromatids separate to opposite poles.

Telophase

Nuclear envelope reforms around separated chromosomes.

Cytokinesis

Division of cytoplasm following mitosis.

Somatic Cells

Body cells that undergo mitosis for growth.

Diploid Cells

Cells with two sets of chromosomes (2n).

Haploid Cells

Cells with one set of chromosomes (1n).

Mitotic Checkpoints

Regulatory points ensuring proper cell division.

G1 Checkpoint

Checks DNA damage, cell size, and nutrition.

M Checkpoint

Ensures all chromosomes are attached to spindles.

Crossing Over

Exchange of genetic material between homologous chromosomes.

Gametes

Haploid reproductive cells produced by meiosis.

Tetrads

Homologous chromosomes paired during meiosis I; 4 chromatids.

Recombination

Crossing over of non-sister chromatids.

Sister Chromatids

Identical copies of a chromosome.

Non-sister Chromatids

Chromatids from different homologous chromosomes.

Meiosis II

Separates sister chromatids, similar to mitosis.

Independent Assortment

Random distribution of chromosomes during metaphase I.

Crossover Events

1-3 exchanges per homologous pair in prophase I.

Genetic Variation

Diversity in gene combinations among offspring.

Transcription

Process of synthesizing RNA from DNA.

Pre-mRNA Processing

Modification of pre-mRNA to mature mRNA.

Translation

Converting mRNA into a protein at ribosome.

Central Dogma

Flow of genetic information: DNA to RNA to Protein.

Genotype

An organism's hereditary genetic makeup.

Phenotype

Observable traits resulting from genotype and environment.

Vesicular Transport

Movement of proteins in vesicles within cells.

Initiation

First step of transcription; polymerase binds to promoter.

Elongation

RNA polymerase transcribes RNA downstream.

Termination

End of transcription process.

RNA

Messenger molecule carrying genetic information from DNA.

DNA

Heritable material storing genetic information.

Protein Structure Levels

Primary, secondary, tertiary, and quaternary structural organization.

mRNA

Messenger RNA, carries genetic information from DNA.

rRNA

Ribosomal RNA, component of ribosomes.

tRNA

Transfer RNA, brings amino acids during translation.

Uracil

Nitrogenous base in RNA, replaces Thymine.

TATA box

Promoter region ~25 nucleotides upstream of transcription start.

Transcription initiation complex

Assembly of proteins including RNA Pol II and TBP.

RNA Pol II

RNA polymerase responsible for mRNA synthesis.

Phosphodiester bond

Link between nucleotides in RNA strand.

Polyadenylation signal

Sequence AAUAAA marking end of transcription.

Capping

Addition of modified guanine nucleotide to 5' end.

Tailing

Addition of 50-250 adenine nucleotides to 3' end.

Exons

Coding regions that remain in mature RNA.

Introns

Non-coding regions removed during RNA processing.

Spliceosome

Complex that removes introns and joins exons.

Alternative splicing

Process producing multiple mRNA forms from one gene.

Codons

Triplets of nucleotides coding for amino acids.

A site

Ribosome site for next tRNA during translation.

P site

Ribosome site holding tRNA with growing polypeptide.

E site

Ribosome exit site for tRNA.

Peptide bonds

Links amino acids in a polypeptide chain.

Fidelity

Accuracy of transcription compared to DNA replication.

mature mRNA

Processed mRNA ready for translation.

Hydrogen bonds

Weak interactions between mRNA and tRNA anticodons.

Initiator tRNA

tRNA carrying methionine for translation start.

Small ribosomal subunit

Binds initiator tRNA and mRNA's 5' cap.

Translation start site

AUG codon where translation begins.

Hydrogen bonds

Form between tRNA anticodon and mRNA codon.

Large ribosomal subunit

Completes initiation complex during translation.

GTP

Energy molecule required for translation initiation.

Initiation factors

Proteins assisting in translation initiation.

Codon recognition

Base pairing of tRNA anticodon with mRNA codon.

Peptide bond formation

Catalyzed by rRNA in large ribosomal subunit.

Translocation

Movement of tRNA between ribosomal sites.

A site

Ribosomal site where new tRNA enters.

P site

Ribosomal site holding tRNA with growing polypeptide.