Questions and Answers
Plasma membranes are a feature of:
Which of the following is NOT a component of plasma membranes?
Which of the following is NOT true of the plasma membrane?
N-linked glycosylation is the attachment of a carbohydrate to a nitrogen atom, while O-linked glycosylation is the addition of sugars to the oxygen atom of certain side chains.
Signup and view all the answers
The process of covalently attaching a carbohydrate to a protein or lipid is called:
Signup and view all the answers
In eukaryotes, where does the synthesis of most lipids primarily occur?
Signup and view all the answers
Facilitated diffusion but not passive diffusion requires energy.
Signup and view all the answers
Exocytosis is the process by which material from inside of the cell is packaged into vesicles and excreted into the extracellular medium.
Signup and view all the answers
The following solutes have very low permeability through the plasma membrane:
Signup and view all the answers
Water can freely diffuse through animal cell membranes.
Signup and view all the answers
Study Notes
Plasma Membranes
- Plasma membranes are present in all types of cells, including prokaryotic and eukaryotic cells.
- Key components of plasma membranes include phospholipids, cholesterol, glycosylated proteins, and glycolipids.
Composition and Structure
- Glycosylated nucleic acids are NOT a component of plasma membranes.
- The extracellular and intracellular leaflets of the plasma membrane are NOT highly symmetrical, contrasting with a common misconception about their structure.
- Peripheral proteins exist on the membrane surface, while integral proteins are embedded, spanning the membrane.
Glycosylation
- N-linked glycosylation involves attaching carbohydrates to the nitrogen of asparagine residues, while O-linked glycosylation attaches sugars to the oxygen of serine or threonine residues.
- Glycosylation is a process for covalently connecting carbohydrates to proteins or lipids, enhancing their functionality.
Lipid Synthesis
- Most lipid synthesis occurs at the cytosolic leaflet of the smooth endoplasmic reticulum (ER) membrane due to interactions with the endomembrane system and cytosol.
Transport Mechanisms
- Facilitated diffusion does NOT require energy, while passive diffusion also operates without it.
- Exocytosis involves packaging materials within vesicles for secretion from the cell into the extracellular space.
Membrane Permeability
- Charged polar molecules and macromolecules exhibit very low permeability through the plasma membrane, limiting their passive transport.
- Water cannot freely diffuse through animal cell membranes, highlighting the regulated nature of cellular water transport.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on plasma membranes with this ANSC 221 Quiz 4 flashcard set. Each card presents a question with multiple-choice answers, focusing on cell biology and the components of plasma membranes. Perfect for studying before your next exam!
