Intermediate filaments provide structural support to cells, maintaining their shape and mechanical stability.

Gap junctions, primarily composed of connexins, enable direct cytoplasmic exchange of ions and small molecules between adjacent cells, facilitating coordinated cellular responses.

Cholesterol is essential for maintaining plasma membrane integrity and stability.

Collagen is not a transport protein; examples of transport proteins include aquaporins, proton pumps, and potassium channels.

Hypotonic solutions can cause water to move into the cell, potentially leading to cell swelling (not shrinkage).

Pinocytosis is the type of endocytosis where cells engulf small droplets of extracellular fluid and dissolved solutes to form small vesicles for internalization.

The sodium-calcium exchanger is an example of an antiporter, exchanging sodium and calcium ions in opposite directions across the membrane.

Glucose typically requires facilitated diffusion to cross the cell membrane, as it is a large, polar molecule.

Secondary active transport depends on the energy stored as an ion gradient by primary active transport, rather than directly using ATP.

Endocytosis involves inward budding of the plasma membrane, facilitated by clathrin and dynamin, while exocytosis involves vesicle fusion with the plasma membrane, mediated by SNARE proteins and synaptotagmin.

Physical changes, such as water freezing, are not chemical reactions; burning paper and cooking are chemical reactions.

ATP is the energy currency of the cell, not genetic material or a DNA subunit.

DNA polymerase is the enzyme responsible for synthesizing DNA during cell replication.

Enzymes decrease the activation energy of chemical reactions, increasing the reaction rate. Eacatalyzed<Eauncatalyzed

Cofactors are not consumed during enzyme catalysis; they assist enzymes and can be organic or inorganic.

Competitive inhibitors bind to the active site of enzymes, blocking substrate binding.

Metabolic pathways process substrates through multiple intermediate steps to produce final products.

The correct order of aerobic cellular respiration stages is: Glycolysis → Pyruvate oxidation → Krebs cycle → Electron transport chain and chemiosmosis.

In chemiosmosis, ions diffuse from high to low concentration across a membrane.

Glycolysis breaks down sugar molecules (glucose) into pyruvate and occurs in the cytoplasm, not the mitochondria, and does not require oxygen.

At the end of pyruvate oxidation, the two carbon atoms from pyruvate are attached to CoA, forming acetyl-CoA.

After hydrolysis, maltose (a disaccharide) yields two glucose molecules, each entering the Krebs cycle twice, for a total of four cycles.

Electrons from NADH2 ultimately react with oxygen at the end of the electron transport chain, forming water. NADH2+O2→H2O

An uncoupling agent that diminishes the proton gradient across cristae leads to decreased production of ATP.