29 Questions
What is the orientation of phospholipid molecules in the plasma membrane?
Hydrophobic tails inside and hydrophilic heads outside
What prevents polar substances from crossing the plasma membrane?
The nonpolar nature of the hydrophobic ends
What is the function of glycophospholipids embedded in the plasma membrane?
To transport molecules across the membrane
What is the purpose of the nuclear envelope's pores?
To allow molecules to move between nucleus and cytoplasm
What is the function of rough endoplasmic reticulum (RER)?
To synthesize proteins that are involved in all of the above
Where are lipids and phospholipids synthesized?
In the Golgi complex
What is the primary function of microvilli in the intestine?
To increase the surface area of the tissue
What is the main difference between plants and animals in terms of nutrition?
Plants are autotrophic, while animals are heterotrophic
What is the primary function of the plasma membrane?
To act as a selective gatekeeper
What type of interactions are responsible for membrane function?
Hydrophilic and hydrophobic interactions
What is the permeability of artificial membranes composed of pure phospholipid or phospholipid and cholesterol?
Permeable to gases and small molecules, but impermeable to water and hydrophilic molecules
What is the function of transport proteins in the membrane?
To regulate the movement of substances into the cell
What is the primary function of transporter proteins in cells?
To specifically bind to substrate molecules and facilitate their transport
Which type of molecules can cross the cell membrane through diffusion?
Lipid-soluble molecules, gases, and urea
What is the difference between facilitated diffusion and active transport?
Active transport requires energy, while facilitated diffusion does not
What is the purpose of gated channels in the cell membrane?
To regulate the flow of charged substances
How do voltage-gated channels open or close?
When the ionic charge across the membrane changes
What is the direction of facilitated diffusion?
With the concentration gradient
What is the characteristic of antiporter kinetics?
Simultaneous transport of substrates in both directions
What is the function of adenine nucleotide translocase in the mitochondria?
To catalyze 1:1 exchange of ADP for ATP across the inner mitochondrial membrane
What is the direction of diffusion?
From an area of high concentration to an area of low concentration
What is the effect of a steeper concentration gradient on the diffusion rate?
Faster diffusion rate
Which of the following molecules can diffuse directly through the lipid bilayer?
Oxygen
What is the requirement for simple diffusion?
No use of transport proteins
What is the outcome of meiosis?
Four haploid daughter cells
During which stage of meiosis do homologous chromosomes separate?
Anaphase I
What is the stage of meiosis immediately preceding cytokinesis?
Telophase II
During which stage of meiosis do sister chromatids separate?
Anaphase II
How many chromosomes are present in the daughter cells of meiosis I?
Half the number of the parent cell
Test your knowledge of cell structure and function, including the plasma membrane, nucleus, and chromosomes. Learn how the plasma membrane regulates what crosses into the cell and how the nucleus controls the cell's genetic material.
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