Cell Biology Quiz on Membranes and Organsims

Viruses are composed of a nucleic acid (DNA or RNA) and a protein coat (capsid). Their structure can be helical, icosahedral, or complex.

Viruses need a host cell to reproduce, as they cannot reproduce on their own. They hijack the host cell's mechanisms.

Unicellular organisms include prokaryotes (bacteria, archaea) and eukaryotes (protozoa, algae, some fungi).

Multicellular organisms (plants and animals) have cells with specialized functions, organized into tissues, organs, and systems.

The endocrine and nervous systems coordinate the function of organs and tissues in multicellular organisms.

A system that exchanges matter and energy with its surroundings. Cells are open systems because they take in nutrients and release waste products.

A semi-permeable barrier that controls what enters and exits the cell. It allows some molecules to pass through while blocking others.

A measure of disorder or randomness in a system. Cells need energy to maintain a stable level of order.

DNA, which contains all the information needed for a cell's structure and function. It's passed on during cell division.

Cells need information about their surroundings, such as the presence of nutrients or toxins, to adapt.

Communication networks within and between cells. They use signals like ions, proteins, and messengers to coordinate activities.

Both types of cells have cell membranes, ribosomes, DNA, and cytoplasm. However, eukaryotes have a nucleus and other membrane-bound organelles, while prokaryotes do not.

Cells are mainly composed of organic compounds like proteins, carbohydrates, lipids, and nucleic acids. These molecules contain carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

Regions within the cell membrane formed by proteins with hydrophobic surfaces that interact with the hydrophobic tails of membrane lipids.

Membrane proteins perform various roles, including transport, enzymatic activity, signal transduction, intercellular joining, cell-cell recognition, and cytoskeleton/ECM attachment.

The cell membrane isn't rigid, but rather a dynamic structure where phospholipids move freely and proteins are embedded like tiles in a mosaic.

Temperature, cholesterol levels, and fatty acid saturation influence membrane fluidity. Low temperatures make membranes more rigid, while cholesterol acts as a buffer, and unsaturated fatty acids increase fluidity.

These are membrane-enclosed regions within eukaryotic cells, like mitochondria, endoplasmic reticulum, Golgi apparatus, and nucleus. They isolate specific processes.

They create boundaries for different biological processes, provide a large surface area for metabolic reactions, and allow for coordinated regulation of these processes.

The cytoskeleton provides structure and stability to membrane compartments or organelles, ensuring their proper localization within the cell.

The plasma membrane defines the cell boundary, separating the internal environment from the external environment.

A thick outer covering of the plasma membrane, composed of carbohydrate chains attached to lipids and proteins. It acts as a protective layer and plays a crucial role in cell recognition and communication.

The glycocalyx plays a vital role in various cellular functions including: protecting the cell membrane, enabling the immune system to recognize foreign invaders, facilitating cell adhesion, and guiding embryonic development.

The cell membrane is selectively permeable, meaning it allows some substances to pass through while blocking others. This controlled passage ensures the cell maintains its internal environment and functions properly.

The difference in electrical charge between the inside and outside of a cell. This charge difference is essential for cellular processes like nerve impulses and muscle contractions.

The glycocalyx of cancer cells often changes, becoming more complex or altered. These changes can help the immune system recognize and target the cancerous cells.

A type of membrane transport protein facilitating the movement of a single molecule across a membrane. It can be an ion channel or a carrier protein.

Movement of molecules across a cell membrane without requiring energy from the cell. Types include simple and facilitated diffusion, and osmosis.

The movement of water across a semi-permeable membrane from a region of higher water concentration to a region of lower water concentration.

The ability of a solution to change the shape (size) of a cell by influencing its water volume.

A solution with the same solute concentration as the cytosol of a cell. The cell maintains its normal shape and volume.

The movement of molecules across a cell membrane requiring energy expenditure, usually ATP.

Directly uses ATP hydrolysis to move molecules against their concentration gradient. Requires specific carrier proteins.

Indirectly uses energy from an existing concentration gradient to transport molecules across the membrane, often couples another molecule's movement, like the sodium-glucose transporter.

A type of membrane receptor that acts as both a channel and a receptor. It controls the flow of ions across the cell membrane by opening or closing the channel when a specific ligand binds to it.

A type of membrane receptor that has an intracellular enzyme activity, often a tyrosine kinase. It is activated by ligand binding, leading to phosphorylation of proteins and triggering signal transduction cascades.

The largest family of cell surface receptors, involved in a wide range of signaling pathways. They associate with G proteins on the cytoplasmic side. Ligand binding activates the G protein, leading to intracellular signaling events.

A type of G protein composed of three subunits: alpha, beta, and gamma. The alpha subunit has GTPase activity, and its activation leads to signaling pathways.

A signaling pathway activated by some G protein-coupled receptors. It involves the production of cyclic AMP (cAMP), a second messenger that regulates various cellular processes.

A signaling pathway activated by some G protein-coupled receptors. It involves the production of diacylglycerol (DAG) and inositol triphosphate (IP3), both second messengers with different roles in signaling.

The process by which cells attach to each other and to the extracellular matrix (ECM). It is essential for tissue formation and function.

A family of cell adhesion molecules that link the cytoskeleton to the ECM. They play a role in cell signaling and migration.