Molecular and Cellular Biology Overview

These flashcards cover key concepts and vocabulary from the lecture on protein synthesis, apoptosis, endoplasmic reticulum functions, and intracellular transport.

Apoptosis

A regulated process that eliminates redundant or damaged cells, with aberrant apoptosis linked to cancer and neurodegenerative diseases.

Caspases

Proteases that activate proteins involved in dismantling the cell during apoptosis.

Endoplasmic Reticulum (ER)

An organelle involved in protein synthesis and lipid synthesis, consisting of Rough ER, which is studded with ribosomes, and Smooth ER

Protein Synthesis

The process where ribosomes translate mRNA sequences to synthesize polypeptide chains, which then fold into functional proteins.

Cotranslational Import

A process where ribosomes synthesize proteins directly into the endoplasmic reticulum membrane during translation.

Signal Recognition Particle (SRP)

A ribonucleoprotein that recognizes signal sequences and halts translation until the ribosome is situated at the ER.

Glycosylation

The addition of carbohydrate chains to specific proteins, crucial for protein folding and stability.

Calcium Handling

The mechanisms by which cells control intracellular calcium levels to maintain cellular functions and prevent precipitation of phosphates.

Vesicular Transport

The process by which materials are transported between organelles and the cell membrane via vesicles.

Translocon

A protein complex in the ER membrane that facilitates the translocation of polypeptides into the ER lumen during cotranslational import.

Endoplasmic Reticulum (ER) Functions

is involved in the synthesis of proteins and lipids, as well as the transport and processing of molecules within the cell.

Functions of Smooth ER

responsible for lipid synthesis, detoxification of drugs and poisons, and calcium ion storage.

Functions of Rough ER

is studded with ribosomes and synthesizes proteins destined for secretion or for use in lysosomes.

Protein Folding

the process by which a polypeptide chain folds into its functional three-dimensional structure, critical for protein function.

Overview of Protein Synthesis

involves transcription of DNA to mRNA in the nucleus, followed by translation of mRNA to form polypeptides at ribosomes.

Rough ER and Protein Translation

Ribosomes attached to the rough ER translate mRNA into polypeptides, which enter the ER for folding and modification.

Cotranslational Protein Import

ribosomes synthesize proteins directly into the ER, facilitating immediate processing and transport.

Proteins Targeted to Mitochondria

Proteins destined for mitochondria contain specific signal sequences that guide them through protein import pathways into mitochondria.

Endocytic Pathways of Protein Sorting

involve the internalization of proteins and their sorting to different cellular compartments, including lysosomes.