#1
Which of the following molecules is a major component of cellular membranes?
Phospholipid
ExplanationPhospholipids form the basic structure of cellular membranes.
#2
What is the primary function of cellular membranes?
Regulation of molecular movement
ExplanationCellular membranes control the movement of substances in and out of the cell.
#3
Which structure is responsible for the selective permeability of the cellular membrane?
Phospholipid bilayer
ExplanationThe phospholipid bilayer acts as a barrier, allowing only specific molecules to pass.
#4
Which process involves the engulfment of particles by the cellular membrane to form a vesicle?
Endocytosis
ExplanationEndocytosis is the process of bringing substances into the cell via vesicle formation.
#5
Which of the following is NOT a type of cellular membrane junction?
Cellulose junction
ExplanationCellulose is not involved in cellular junctions; options include tight junctions, gap junctions, and desmosomes.
#6
What is the main function of cholesterol in the cellular membrane?
Stabilize the membrane
ExplanationCholesterol helps maintain the fluidity and stability of the cellular membrane.
#7
What term describes the movement of molecules from an area of high concentration to an area of low concentration across a cellular membrane?
Simple diffusion
ExplanationSimple diffusion is the passive movement of molecules down their concentration gradient.
#8
What is the role of integral membrane proteins?
All of the above
ExplanationIntegral membrane proteins perform various functions including transport, signaling, and structural support.
#9
Which organelle is responsible for synthesizing phospholipids for cellular membranes?
Endoplasmic reticulum
ExplanationThe endoplasmic reticulum synthesizes phospholipids, which are essential for cellular membranes.
#10
Which type of membrane transport requires energy input to move molecules against their concentration gradient?
Active transport
ExplanationActive transport uses energy to pump molecules against their concentration gradient.
#11
Which cellular membrane component plays a crucial role in cell signaling?
Glycocalyx
ExplanationThe glycocalyx serves as a signaling molecule and is involved in cell recognition.
#12
Which organelle is responsible for the degradation of cellular components and recycling of materials?
Lysosome
ExplanationLysosomes contain enzymes that break down cellular waste and foreign material for recycling.