Chap 3 Flashcards
What is the function of the nucleus in a cell?
Control center, stores DNA
The nucleus regulates gene expression and maintains the integrity of genes.
What is the primary role of mitochondria?
Produces ATP
Mitochondria are often referred to as the powerhouse of the cell.
What is the function of ribosomes?
Protein synthesis
Ribosomes can be found free in the cytoplasm or attached to the endoplasmic reticulum.
What are the two types of Endoplasmic Reticulum?
Smooth and Rough
Rough ER is studded with ribosomes, while Smooth ER is involved in lipid synthesis.
What is the role of the Golgi apparatus?
Packages and modifies proteins
It is essential for sorting and delivering proteins to their destinations.
What do lysosomes do?
Breaks down waste
Lysosomes contain digestive enzymes to degrade waste materials and cellular debris.
What is the function of the cytoskeleton?
Provides structure and transport pathways
The cytoskeleton is made up of microfilaments, intermediate filaments, and microtubules.
What is the role of channel proteins?
Facilitate the movement of ions across membranes via facilitated diffusion
Channel proteins are specific to certain ions or molecules.
What is the structure of the phospholipid bilayer?
Hydrophilic heads face outward, hydrophobic tails face inward
This arrangement is crucial for the formation of cell membranes.
What type of transport requires no energy?
Passive transport
Includes processes like simple diffusion, facilitated diffusion, and osmosis.
Define simple diffusion.
Movement of molecules from high to low concentration
It occurs directly through the phospholipid bilayer.
What is facilitated diffusion?
Uses carrier proteins or ion channels
It helps transport substances that cannot directly cross the lipid bilayer.
What is osmosis?
Diffusion of water across a membrane
Osmosis is vital for maintaining cell turgor and homeostasis.
What type of transport requires energy?
Active transport
Active transport moves molecules against their concentration gradient.
Describe the sodium-potassium pump.
Pumps 3 Na+ out and 2 K+ in, requiring ATP
This pump is crucial for maintaining the electrochemical gradient across cell membranes.
