Chp 5 Biology

Describe the structure of a transport protein.

A transport protein completely spans the cell membrane, and allows certain molecules or ions to diffuse across the membrane.

The molecule that provides the energy needed for active transport is _________. -Sodium -Water -ATP -Glucose

ATP

The sodium-potassium pump is an example of _____________ transport.

Active

What type of transport are exocytosis and endocytosis? -Passive -Active -Diffusion -Osmosis

Active

Which of the following is an appropriate analogy for active transport? Active transport is like pushing something uphill. Active transport is like pushing something downhill. Active transport is like pushing something across a level surface. Active transport is like pushing something in a circle.

Active transport is like pushing something uphill.

What is the difference between active and passive transport across the cell membrane?

Active transport requires energy while passive transport does not.

Why do adjustments constantly need to be made to a system to maintain homeostasis?

Adjustments constantly need to be made because the internal and external environments of a cell are constantly changing.

The type of transport proteins involved in facilitated diffusion are ______________. - Carrier proteins - Channel proteins - Gated channel proteins - All of the above

All of the above

In what type of cell is the sodium-potassium pump found? -Almost all plant cells -Almost all animal cells -Almost all bacterial cells -Almost all cells

Almost all animal cells

In which part of the neuron is the sodium-potassium pump active? -Dendrites -Axons -Cell Bodies -Terminals

Axons

Which of the following type of protein allows water to diffuse across the membrane very quickly? -Channel protein -Carrier protein -Ion channel -None of the above

Channel protein

In diffusion, what is the concentration gradient?

Diffusion is the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration. The concentration gradient is the difference in the concentrations of the molecules in the two areas.

What is the definition of endocytosis?

Endocytosis is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane.

What is the end result of diffusion? -Passive transport -Osmosis -Equilibrium -Concentration gradient

Equilibrium

What is the definition of facilitated diffusion?

Facilitated diffusion is the diffusion of solutes through transport proteins in the plasma membrane.

Pinocytosis is the process of sending liquids or dissolved substances out of the cell. -True -False

False

True or false A solution with the same concentration of solutes compared to another is called a hypotonic solution.

False

True or false Channel proteins and carrier proteins transport molecules in the same way.

False

Explain how a molecule like glucose would be transported against its concentration gradient from the inside to the outside of the cell.

Glucose would be moved from an area of low concentration to high concentration across the cell membrane through a process called exocytosis.

What is homeostasis?

Homeostasis is the balance or equilibrium within the cell or body, and an organism's ability to maintain a constant internal environment.

What is the name of the adjusting systems within a cell to maintain homeostasis? Equilibrium Homeostatic regulation Active transport Endocytosis Exocytosis

Homeostatic regulation

Classify each of the following as hydrophobic or hydrophilic: -Interior of the cell membrane -Calcium -Carbon dioxide -Oxygen -Water

Hydrophobic Hydrophilic Hydrophobic Hydrophobic Hydrophilic

What type of solution is 2% NaCl compared with 1% NaCl? -Hypertonic -Hypotonic -Isotonic -None of the above

Hypertonic

What happens to a red blood cell when it is placed in a hypertonic solution? -It swells -It shrinks -It stays the same -It swells and then shrinks

It shrinks

What happens to a cell that has a rigid cell wall when placed in a hypotonic solution? -It will swell until the cell lyses -It will swell until the cell is turgid -It will lose water to the environment, shrivel, and probably die -It will pull away from the cell wall

It will swell until the cell is turgid

What would happen to a freshwater fish in the ocean? -Its cells would swell and the fish would die -Its cells would shrink and the fish would die -Its cells would not swell or shrink -Its cells would swell and then shrink

Its cells would shrink and the fish would die

How are larger molecules transported across the cell membrane?

Larger molecules are transported by endocytosis and exocytosis

What is the definition of diffusion? -Moving from areas of low amounts to areas of high amounts -Moving from areas of high amounts to areas of low amounts -Mixing together -Keeping things separate

Moving from areas of high amounts to areas of low amounts

What is the charge of the inside of a cell relative to the outside of the cell? -Negative -Positive -Neutral -None of the above

Negative

Facilitated diffusion is a type of ____________________ . - Passive transport - Active transport - Osmosis - Energy transfer

Passive transport

If a solid substance needed to enter the cell, what is the name of the process that would bring it inside? -phagocytosis -pinocytosis -vesicle transport

Phagocytosis

Gated channel proteins can NOT be opened by which of the following? Chemical or electrical signals -Temperature -Mechanical force -Pressure

Pressure

What would happen if the sodium-potassium pump in a cell broke? -Sodium would build up inside the cell, and potassium would build up outside the cell -Sodium would build up outside the cell, and potassium would build up inside the cell -Sodium and potassium would build up inside the cell -Sodium and potassium would build up outside the cell

Sodium would build up inside the cell, and potassium would build up outside the cell

Explain how ATP supplies the energy for the sodium-potassium pump.

The ATP transfers one of its phosphate groups directly to a carrier protein, causing it to change its shape, moving the ion across the membrane.

Describe the forces driving the diffusion of ions across the plasma membrane that together cause the electrochemical gradient.

The first force is the chemical force caused by the ions' concentration gradient, and the second force is the electrical gradient caused by the membrane potential.

What does it mean for a cell membrane to be selectively permeable?

The membrane has control over what molecules or ions can enter or leave the cell.

Explain how osmotic pressure helps provide support in plants.

The osmotic entry of water helps maintain the turgor pressure which helps plants stand up straight.

How are hormones such as dopamine released from a cell?

They are transported to the membrane in vesicles, where they are released from the cell through exocytosis.

How do contractile vacuoles help in controlling osmosis?

They remove excess water from a cell. For example, freshwater protists have a contractile vacuole. The vacuole is surrounded by several canals, which absorb water by osmosis from the cytoplasm. After the canals fill with water, the water is pumped into the vacuole. When the vacuole is full, it pushes the water out of the cell through a pore.

How are smaller molecules and ions transported across the cell membrane? -Endocytosis and exocytosis -Carrier proteins -ATP -Transport proteins

Transport proteins

How do larger molecules cross the cell membrane?

Transport proteins within the membrane allow these molecules to pass through the membrane, and into or out of the cell.

The sodium-potassium pump helps maintain cell potential, regulate cellular volume, and keep cells from having too much sodium inside. -True -False

True

True or false Gated channel proteins have a binding site that is specific for a given molecule or ion.

True

True or false Ion channels are very specific - they allow only certain ions through the cell membrane.

True

In the sodium-potassium pump, how many potassium (K+) ions are exchanged for every three sodium (Na+) ions? -one -two -three -four

Two

If a large molecule like glucose needed to be removed from a cell, which type of transport would be used? -Active transport -Passive transport -Vesicle transport -None of the above

Vesicle transport

Which of the following is NOT a type of endocytosis? -phagocytosis -pinocytosis -vesicle transport

Vesicle transport

Which of the following is NOT a type of passive transport? -Diffusion -Osmosis -Facilitated diffusion -Vesicle transport

Vesicle transport

Describe what happens during exocytosis.

Vesicles fuse with the plasma membrane and release their contents to the outside of the cell.

Give an example of a molecule transported by a transport protein.

Water, sodium and glucose are examples of molecules transported by transport proteins.

Is osmosis a form of diffusion? Explain your answer.

Yes, osmosis is a form of diffusion. Water moves from areas of high concentration to areas of low concentration, across the cell membrane.

Active transport pumps molecules and ions against a ___________________________.

concentration gradient

Which characteristic of life does a selectively permeable membrane help maintain? -growth -evolution -response to stimuli -homeostasis

homeostasis

Animal cells tend to do best in a(n) _____________ environment.

isotonic

On which side of the cell is there a higher concentration of sodium (Na+) - inside or outside?

outside

List three types of substances that might need to be expelled from the cell.

proteins waste products toxins

Where does the energy come from to do active transport?

respiration

Which organelle transports molecules to and from the cell membrane during exocytosis and endocytosis? -Ribosomes -Nucleus -Vacuole -Vesicle

vesicle