Bio 160 ch 3 study questions

Phospholipids are important components of cell membranes. Like triglycerides, phospholipid molecules contain _________tails linked to a glycerol portion, but in phospholipids a group containing ________replaces one of the fatty acid tails.

Fatty acid: phosphate

Some drugs work by preventing infection bacteria from sticking inside your body. Knowing this, the drugs likely work by _____?

Interfering with the bacterium's glycocalyx

The plasma membrane of an animal is mainly composed of ____________, which is arranged into two layers of fatty acid tails that point toward each other.

Phospholipids; This type of lipid forms the basis of the membrane's structure.

The plasma membrane is _________ meaning it lets some substances through and not others.

Semipermeable; Membrane will allow very small molecules and non-polar molecules to pass freely. Large and charged molecules are not able to pass unless there is a channel protein available to them (facilitated transport).

facilitated transport

The movement of molecules across the cell membrane without the use of ATP, but with the help of a protein.

One day during the summer you and some friends made ice cream using an electric ice cream maker. To chill the ice cream you used salt and ice. After the ice cream is made, you drain the salty ice-water onto the grass. A few days later you noticed a yellow circle of dead grass where the ice cream maker had been placed. What happened?

The salty ice-water was hypertonic to the grass cells and caused them to plasmolyse.

___________ proteins facilitate the movement of ions and charged molecules from one side of the membrane to the other side.

Transport

Diffusion occurs because of random molecular movement. T/F

True; This is called "Brownian" movement and is due to the natural vibration of atoms. So a cell does not need to expend any energy for the passive processes of diffusion and osmosis.

How might you describe the molecule labelled A

a channel protein; This type of channel protein might be used in either facilitated transport or active transport.

what would you expect to be the monomer of the substance that forms the cytoskeleton?

amino acids

Which are the prokaryotic cells?

bacteria and archaea

What is the role of the cytoskeleton in cells?

cellular scaffold cell movement intracellular transport

Chlorosis is a viral disease of plants. Affected plants are unable to use sunlight to manufacture sugars, and tend to get yellow and weak. Given this information, the virus most likely affects the _________ of the plant cells.

chloroplasts

In the plasma membrane of an animal cell, the __________ molecules serve to patch and control fluidity of the membrane.

cholesterol

What is found in both prokaryotic and eukaryotic cells?

cytoplasm, a plasma membrane, DNA(nucleus), ribosomes

Concentration gradient

difference in solute concentration in one region compared to another. This will result in a natural diffusion from an area of high concentration to an area of low concentration.

The presence of a membrane-enclosed nucleus is a characteristic of ________.

eukaryotic cells

A scientist needs to revive some dehydrated cells. What type of solution should they soak the seeds in?

hypotonic

Paramecium have special organelles called contractile vacuoles that continually eliminate excess water from the cell. Without the contractile vacuole the paramecium would swell up and die. The presence of these organelles tells you that the paramecium's environment is _____?

is hypotonic to the paramecium ; If the paramecium is constantly swelling with excess water, it must always have water entering its cell. Since water is flowing into the cell, the environment must be hypotonic.

Which organelle do phagocytes use to digest engulfed particles?

lysosome

The fluid mosaic model of the membrane describes the membrane as

made of proteins embedded into a fluid phospholipid bilayer

If a cell does not split properly during cell division, it might be due to defective _____ of the cytoskeleton?

microfilaments

If a cell does not split properly during cell division, it might be due to defective ________

microfilaments

Single-celled organisms called paramecia are covered in thousands of cilia. Thus, the surface of these cells contains lots of _____?

mirotubules

Brain cells require a lot of energy in the form of ATP to function normally. We would expect brain cells to contain a lot of _____?

mitochondria

What are found in animal cells?

nucleus, chromatin, nucleolus, perixisome, endoplasmic reticulum, rough er, smooth er, cytoskeleton, microtubules, centrosome, intermediate filaments, microfilaments, plasma membrane, lysosome, Golgi apparatus, cytoplasm, mitochondria

Where do we find carbohydrates?

on the exterior surface of the cell (as part of the glycocalyx).

The rough ER is named because it has an abundance of which of _____ on it?

ribosomes

When a body builder puts on muscle, they have to produce a lot of the protein microfilament called actin. This protein is responsible for the contraction of muscle cells. Thus, you would expect that muscle cells must contain a lot of _____?

ribosomes

What are the structures of the endomembrane system?

rough ER, Golgi complex, vesicles

Most of the lipids in your body are made in the liver. As such, you would expect liver cells to contain a lot of _____?

smooth endoplasmic reticula

A key role of peroxisomes includes:

the ability to perform lipid metabolism and chemically neutralize free radicals.

If you place a potato in a hypertonic solution

the potato cell will dehydrate and experience plasmolysis

How do lysosomes dispose of cellular waste?

they produce enzymes that digest and break down the waste

The epithelial lining of kidney tubules needs to stop any leakage of fluid in the kidneys into adjacent cells. Thus, the cells that lie the kidney tubules are joined by

tight junctions

The epithelial lining of kidney tubules needs to stop any leakage of fluid in the kidneys into adjacent cells. Thus, the cells that lie the kidney tubules are joined by _____?

tight junctions

A primary function of the nucleus in eukaryotic cells is:

to contain the cell's genetic material.

The specific function of a membrane is dependent on:

type of membrane proteins

The specific function of a membrane is dependent on? ***proteins perform all the work and functions of a cell. Thus, _____ perform the work from the cell

type of membrane proteins

Cell theory is

widely accepted by all scientists as true to the best of our knowledge

Which of the following statements regarding diffusion is false?

-Brownian motion occurs even after equilibrium is reached and no net change is apparent. -Diffusion is a result of the movement of atoms and molecules. -Diffusion is driven by concentration gradients. -Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated. (This statement has the direction of particles going in the wrong direction. Diffusion will always move towards the area of lower concentration.)

A cell containing 25% sucrose is placed in a beaker containing distilled water. The membrane is not permeable to sucrose.

-The distilled water contains 0% sucrose, Distilled water contains no solutes -The beaker is hypo-osmotic to the cell, The beaker has a lower solute concentration -The cell will take on water, so the environment is hypotonic -Osmosis will occur, We know this because the solute (sucrose) cannot pass through the cell membrane.

Two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place. The water will

-exhibit a net movement to the side with higher solute concentration; the water will in effect "dilute down" the higher proportion of solutes towards equilibrium. -exhibit a net movement to the side with lower water concentration.

How might you describe the molecule labeled C?

-part of the extracellular matrix -part of the glycocalyx The glycocalyx is the sticky external coating of a cell, and the structure shown here is part of it. -a carbohydrate chain

A cell containing 5% salt is placed into a beaker with 25% salt. The salt CANNOT pass through the membrane.

-the beaker contains a hypertonic solution; The term hypertonic tells us that water will leave the cell. This is exactly what will happen via osmosis with 5% salt in the cell and 25% salt in the beaker. -the cell is hypo-osmotic to the beaker

What types of cells would contain golgi complex

Brain cells of a lion leaf cells of a plant skin cell of a cat

What are found in plant cells?

Plasmodesmata, cell wall, plasma membrane, cytoplasm, central vacuole, cytoskeleton, endoplasmic reticulum, nucleus, ribosomes, Golgi apparatus, mitochondria, peroxisome, plastid, chloroplast

Question 70.3 pts What is the solute of a 15% sucrose solution?

Sucrose