Biology Chapter 8 Lesson 3

Questions and Answers

What is diffusion?

Movement of proteins through a membrane

Movement of water across a membrane

Movement of particles from high concentration to low concentration (correct)

Movement of particles from low concentration to high concentration

What is osmosis?

Diffusion of water across a selectively permeable membrane

Match the following terms with their definitions:

Selective Permeable Membrane = A membrane that allows certain materials to pass through, but not others Facilitated Diffusion = Diffusion that uses carrier proteins to help molecules move through Phospholipid = Molecule that makes up cell membranes with a hydrophilic head and hydrophobic tails Hydrophilic = Water loving substances that easily mix with water

What is the definition of active transport?

The movement of a substance across a cell membrane against its concentration gradient, through specific transport proteins and requiring ATP Signup and view all the answers

Passive transport requires energy.

False Signup and view all the answers

Iodine is an indicator for _____________.

starch Signup and view all the answers

During the starch lab, molecules of _____________ diffused through the baggie.

iodine Signup and view all the answers

During the starch lab, the starch did not move out of the baggie because ______________________.

starch is too big Signup and view all the answers

Both active transport and facilitated diffusion involve the use of _________________ to help molecules move through the membrane.

proteins Signup and view all the answers

What is endocytosis?

Intake of molecules by the cell Signup and view all the answers

Hypertonic solutions have a lower solute concentration than the cell.

False Signup and view all the answers

What process involves the engulfing of large particles by a cell?

Phagocytosis Signup and view all the answers

What is the primary function of ATP in cellular processes?

To provide energy Signup and view all the answers

Study Notes

Cell Transport Concepts

Diffusion: Movement of particles from an area of high concentration to an area of low concentration, establishing equilibrium.
Osmosis: Specifically refers to the diffusion of water through a selectively permeable membrane, critical for maintaining cell homeostasis.
Selectively Permeable Membrane: A barrier that only allows certain substances to pass through while restricting others, important for controlling cellular environments.

Types of Transport

Facilitated Diffusion: Uses carrier proteins to assist the movement of molecules across the membrane from high to low solute concentration without energy expenditure.
Passive Transport: Diffusion across a biological membrane with no energy cost; includes diffusion, osmosis, and facilitated diffusion.
Active Transport: Movement of substances against their concentration gradient using specific transport proteins and ATP, crucial for nutrient uptake and waste removal.

Vesicular Transport

Exocytosis: Secretion process where vesicles fuse with the plasma membrane to release molecules outside the cell.
Endocytosis: Intake of extracellular substances through vesicle formation from the plasma membrane, allowing cells to engulf materials.

Phospholipid Structure

Phospholipid: Composed of a hydrophilic "head" (water-attracting) and two hydrophobic "tails" (water-repelling), forming the basis of cellular membranes.
Hydrophilic: Attracted to water; found in the head of phospholipids.
Hydrophobic: Repellent to water; characterizes the tails of phospholipids.

Solutions and Cell Behavior

Hypotonic Solution: Lower solute concentration than inside the cell; leads to cell swelling as water enters.
Hypertonic Solution: Higher solute concentration outside the cell; causes cell shrinkage as water leaves.
Isotonic Solution: Equal solute concentration inside and outside the cell, maintaining cell shape without net movement of water.

Transport Mechanisms Insights

Integral Proteins: Span the entire lipid bilayer, involved in transport and communication across the membrane.
Peripheral Proteins: Located on the membrane's surface, lacking penetration through the bilayer; serve as enzymes and signaling molecules.
Bulk Transport: Includes endocytosis and exocytosis to transport large molecules and particles across the cell membrane.

Additional Processes

Pinocytosis: A form of endocytosis that specifically involves the uptake of liquid from the surrounding environment.
Phagocytosis: A specialized type of endocytosis that engulfs large particles or even other cells, vital for immune response.

Lab Context

Iodine as an Indicator: Useful for detecting the presence of starch, illustrating the principles of diffusion in a lab setup.
Starch Movement: Starch remains in a baggie during experiments because its large size prevents it from diffusing out through the membrane.

Description

Test your knowledge on cell transport concepts with this informative quiz. Explore key terms such as diffusion, osmosis, and selectively permeable membranes. Perfect for reviewing essential biological processes related to how substances move across cell membranes.