p.14
Overview of Cell Transport
What is the role of plasmodesmata in plant cells?
Plasmodesmata are channels that allow for transport and communication between plant cells.
p.19
Phospholipid Bilayer Permeability
Which molecules can pass through the phospholipid bilayer by diffusion?
Small nonpolar molecules such as oxygen, carbon dioxide, and steroid hormones.
p.18
Diffusion of Steroid Hormones
What are the characteristics of steroid hormones in terms of size and hydrophobicity?
Steroid hormones are small and mostly hydrophobic.
How does an isotonic environment affect plant cells?
It is bad for plant cells.
p.1
Phospholipid Bilayer Permeability
What is the primary method of cell transport discussed in Lecture 7 of Biology 107?
Diffusion through the phospholipid bilayer.
p.14
Overview of Cell Transport
How do plant cells differ from animal cells in terms of their structure?
Plant cells have a cell wall, chloroplasts, and a central vacuole, which are not present in animal cells.
What is an isotonic environment?
An environment where the solute concentration outside the cell is equal to the solute concentration inside the cell.
p.1
Phospholipid Bilayer Permeability
What characteristic of the phospholipid bilayer affects its permeability?
The hydrophobic core formed by the fatty acid tails of phospholipids.
p.19
Hypertonic Environment
What happens to bacteria cells in a hypertonic environment?
Bacteria cells shrink and may become plasmolyzed.
p.8
Movement of Water Molecules
What do cells contain a lot of?
Cells contain lots of molecules, also known as solutes.
p.16
Phospholipid Bilayer Permeability
What is the primary structure that gases and steroid hormones pass through to enter or exit a cell?
The phospholipid bilayer.
p.13
Hypertonic Environment
What happens to an animal cell in a hypertonic environment?
An animal cell will shrink as water leaves the cell to balance the solute concentration.
What happens to animal cells in an isotonic environment?
Animal cells maintain their normal shape and function.
What type of molecules typically diffuse through the phospholipid bilayer?
Small, nonpolar molecules such as oxygen and carbon dioxide.
p.19
Hypertonic Environment
What happens to animal cells in a hypertonic environment?
Animal cells shrink and become crenated due to water loss.
What is diffusion?
The net movement of molecules into regions of low concentration.
p.12
Hypotonic Environment
What is a hypotonic environment?
An environment where the solute concentration outside the cell is less than inside the cell.
p.13
Hypertonic Environment
Why is a hypertonic environment bad for most cells?
Because the higher solute concentration outside the cell can cause water to leave the cell, leading to cell shrinkage and potential damage.
p.5
Movement of Water Molecules
What is osmosis?
The net movement of water molecules into regions of high solute concentration and low water concentration.
How do gases and steroid hormones diffuse through the cell membrane?
They diffuse through the phospholipid bilayer.
p.13
Hypertonic Environment
What defines a hypertonic environment?
A hypertonic environment is where the solute concentration outside the cell is greater than inside the cell.
p.14
Movement of Water Molecules
What is the function of the central vacuole in plant cells?
The central vacuole stores nutrients and waste products and helps maintain turgor pressure in the cell.
p.19
Hypotonic Environment
What happens to bacteria cells in a hypotonic environment?
Bacteria cells swell but are protected from bursting by their cell wall.
p.15
Hypertonic Environment
Why can't bacteria grow on honey?
Because it is a hypertonic environment and they die by plasmolysis.
p.12
Hypotonic Environment
How does a hypotonic environment affect cells with cell walls, such as plants and bacteria?
It is normal for cells with cell walls.
p.13
Hypertonic Environment
What happens to a plant cell in a hypertonic environment?
A plant cell will undergo plasmolysis, where the cell membrane pulls away from the cell wall due to water loss.
What happens to bacteria cells in an isotonic environment?
Bacteria cells maintain their normal shape and function.
p.2
Overview of Cell Transport
What is the main topic of Lecture 7?
Cell transport, specifically diffusion through the phospholipid bilayer.
p.1
Diffusion of Steroid Hormones
Why can steroid hormones diffuse through the phospholipid bilayer?
Because they are lipid-soluble and can pass through the hydrophobic core of the bilayer.
p.19
Hypertonic Environment
What happens to plant cells in a hypertonic environment?
Plant cells undergo plasmolysis, where the cell membrane pulls away from the cell wall.
p.8
Movement of Water Molecules
What is an example of a cell that contains solutes?
Human red blood cells (RBC).
p.12
Hypotonic Environment
How does a hypotonic environment affect animal cells?
It is bad for animal cells.
What is diffusion in the context of cell transport?
The movement of molecules from an area of higher concentration to an area of lower concentration.
What happens to plant cells in an isotonic environment?
Plant cells become flaccid but do not lose their shape.
How does an isotonic environment affect animal cells?
It is normal for animal cells.
Which types of substances are mentioned in Lecture 7 as diffusing through the phospholipid bilayer?
Gases and steroid hormones.
p.14
Overview of Cell Transport
What organelle is responsible for photosynthesis in plant cells?
Chloroplasts are responsible for photosynthesis in plant cells.
p.19
Hypotonic Environment
What happens to plant cells in a hypotonic environment?
Plant cells become turgid as they take in water, but do not burst due to the cell wall.
p.14
Overview of Cell Transport
What is the primary function of the cell wall in plant cells?
The cell wall provides structural support and protection to the plant cell.
p.19
Hypotonic Environment
What happens to animal cells in a hypotonic environment?
Animal cells swell and may burst (lyse) due to water intake.
