Cell Structure and Genetic Control

Vocabulary flashcards covering cell structure, organelles, membranes, and genetic control of protein synthesis.

Cell

The basic unit of structure and function in living organisms.

Plasma Membrane

A selectively permeable double layer of phospholipids with inserted proteins that surrounds the cell, provides structure, and separates internal structures from the extracellular environment.

Fluid-Mosaic Model

A structural depiction of the plasma membrane showing a flexible phospholipid bilayer embedded with diverse integral and peripheral proteins.

Integral Proteins

Transmembrane proteins that are bound to molecules within the membrane and can span the lipid bilayer multiple times.

Peripheral Proteins

Membrane proteins that are partially embedded in only one face of the phospholipid bilayer.

Nucleus

An organelle enclosed by internal and external nuclear membranes that contains genomic DNA and controls cellular activities.

Cytoplasm

The aqueous contents of the cell located inside the plasma membrane.

Ribosomes

Organelles found free in the cytoplasm or attached to the rough endoplasmic reticulum that function as the primary sites of protein synthesis.

Rough Endoplasmic Reticulum

A membrane system studded with ribosomes on its surface that functions in protein synthesis.

Smooth Endoplasmic Reticulum

A membrane network devoid of ribosomes involved in lipid synthesis, detoxification, and calcium storage and dynamics.

Golgi Apparatus

An organelle that modifies proteins received from the endoplasmic reticulum and packages them into vesicles for secretion or cellular distribution.

Mitochondria

Double-membrane organelles containing inner folds called cristae and a central matrix, responsible for cellular ATP synthesis and energy production.

Lysosomes

Organelles responsible for cellular cleanup, including the destruction of bacteria, damaged organelles, and foreign substances.

Cytoskeleton

A network of interconnected microtubules made of protein filaments that provides cellular support and enables movement.

Gene

A specific region of DNA containing instructions or code for synthesizing a polypeptide chain.

Gene Expression

The multi-step process consisting of transcription, splicing, and translation by which genomic instructions produce a functional protein.

Genetic Transcription

The nuclear process where a DNA template sequence is transcribed into pre-messenger RNA.

Introns

Non-coding regions of pre-messenger RNA that are excised during RNA splicing.

Exons

Coding regions of pre-messenger RNA that remain after splicing and are joined together to form mature mRNA.

RNA Splicing

The post-transcriptional process in the nucleus where non-coding introns are removed and coding exons are joined to yield functional mRNA.

Genetic Translation

The synthesis of a polypeptide chain at the ribosome according to the sequence contained in mRNA, assisted by tRNA.

Codon

A three-base nucleotide sequence on mRNA that corresponds to a specific amino acid or stop signal during protein synthesis.

Anticodon

A three-base sequence on a tRNA molecule that pairs complementarily with an mRNA codon.

Transfer RNA (tRNA)

An RNA molecule that acts as the physical link between mRNA codons and the amino acid sequence during translation.