Cell Biology Overview Quiz

Light microscopy allows viewing dynamic processes in living cells, while electron microscopy requires samples to be fixed and thus provides images of static cells. Electron microscopy offers greater magnification and resolution.

Cell fractionation aims to separate and isolate different organelles from each other, enabling the study of their specific functions. It is done by differential centrifugation where heavier components settle first.

The order of centrifugation separates cell components by density: nucleus (heaviest), then mitochondria, then ribosomes. This is due to their relative sizes and densities.

Microscopy images require interpretation and understanding of the method used to obtain them. This is crucial for judging whether the images are artifact-free and for accurately interpreting the structures and processes observed.

Prokaryotes lack an endoplasmic reticulum, unlike eukaryotes that have a distinct membrane-bound system for protein synthesis and transport.

Plant cells often have larger volumes than animal cells primarily due to the presence of large vacuoles that store water and other substances, contributing to their size and shape.

The surface area of a cell must be large enough to support the volume of the cell for efficient nutrient and waste exchange.

Smooth ER is involved in the synthesis of lipids like oils, phospholipids and steroids.

The Golgi apparatus is a series of flattened sacs that receives, modifies, and sorts proteins and lipids from the ER.

The Golgi apparatus is a series of flattened sacs that receives, modifies, and sorts proteins and lipids from the ER.

The Golgi apparatus modifies and sorts polysaccharides that will be secreted from the cell.

Lysosomes are membrane-bound organelles that contain hydrolytic enzymes, which break down macromolecules and cellular debris.

Mitochondria are double-membrane organelles that are the primary sites of ATP production in eukaryotic cells.

Mitochondria and Chloroplasts contain their own DNA, separate from the nuclear DNA.

Peroxisomes are cellular organelles involved in a variety of metabolic reactions, including lipid metabolism and detoxification of harmful molecules.

Peroxisomes use enzymes to break down hydrogen peroxide molecules, a byproduct of various cellular activities, into water and oxygen.

The cytoskeleton provides structural support, facilitates movement, and helps organize cellular components.

Microfilaments, microtubules, and intermediate filaments are the three main components of the cytoskeleton, each with distinct structures and roles.

Microtubules are hollow tubes composed of tubulin protein subunits and play crucial roles in cell shape, division, and movement.

Microfilaments are composed of the protein actin, arranged in two intertwined strands, responsible for cell movements like crawling and contraction.

Intermediate filaments are fibrous proteins, thicker than microfilaments, providing structural support and anchoring for cells.

Microtubules play a role in chromosome movement during cell division, while microfilaments are involved in the formation of the cleavage furrow during cytokinesis.

Cellular components are separated based on their density and size, allowing for the study of individual organelles.

A process that breaks down macromolecules and cellular debris using hydrolytic enzymes, essential for recycling and removing unwanted material.

The ability of a cell to regulate its internal environment independent of external fluctuations; essential for maintaining stability and proper functioning.

The process by which cells take in material from their surrounding environment through the formation of vesicles.

Diffusion is a passive process that involves the movement of molecules from a region of higher concentration to a region of lower concentration.

Water easily passes through cell membranes because of special protein channels called aquaporins.

A hypertonic solution has a higher concentration of solutes than the cell, causing water to move out of the cell and make it shrink.

A hypotonic solution has a lower concentration of solutes than the cell, causing water to move into the cell and make it swell.

Cholesterol is a type of lipid that helps maintain the fluidity and stability of the cell membrane.

Glycolipids are lipids attached to carbohydrates, found on the outer surface of the cell membrane. They play a role in cell recognition and signaling.

The cell membrane is a selectively permeable barrier that allows some substances to pass through while blocking others.

Integral proteins are embedded within the cell membrane and play a role in transporting molecules across the membrane, acting as channels or carriers.

Microtubules are hollow tubes made of tubulin proteins. They provide structural support, act as tracks for motor proteins to transport cargo within the cell, and play a role in cell division.

Microfilaments are thin, solid rods made of actin proteins. They provide structure, help with muscle contraction, and facilitate cell movement.

Intermediate filaments are fibrous proteins that provide structural support and help anchor organelles in place. They are more stable than microtubules and microfilaments.

Ribosomes are the sites of protein synthesis in cells. Bound ribosomes are attached to the endoplasmic reticulum, while free ribosomes float in the cytoplasm. Bound ribosomes synthesize proteins destined for the endomembrane system or for secretion outside the cell.

The endomembrane system is a network of internal membranes that compartmentalize eukaryotic cells. It includes the nuclear envelope, endoplasmic reticulum (ER), Golgi apparatus, lysosomes, vacuoles, and plasma membrane. The system plays a crucial role in protein and lipid synthesis, processing, and transport.

Prokaryotes are single-celled organisms that lack a nucleus and other membrane-bound organelles characteristic of eukaryotes. They have a simpler structure and are typically smaller than eukaryotic cells.

The plasma membrane is a selectively permeable barrier that encloses the cell, regulating the passage of molecules in and out. It is made of a phospholipid bilayer with embedded proteins.