Laboratory Review 5 : Cell Structure and Function

What regulates the movement of molecules into and out of the cytoplasm?

The plasma membrane (cell membrane).

Why is the plasma membrane important?

It regulates what enters and leaves the cell, helping maintain the cell's internal environment.

What feature distinguishes a prokaryotic cell from a eukaryotic cell?

A prokaryotic cell lacks a membrane-bound nucleus.

What is the major difference between prokaryotic and eukaryotic cells?

Prokaryotic cells lack a membrane-bound nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and membrane-bound organelles.

What structures carry out protein synthesis in both prokaryotic and eukaryotic cells?

Ribosomes.

Name two things found in the nucleus of a eukaryotic cell.

DNA and the nucleolus.

What is the function of the nucleolus?

It produces ribosomal subunits, which are used to form ribosomes.

What organelle carries out photosynthesis in plant cells?

The chloroplast.

What molecule is associated with plant cell walls?

Cellulose.

What is the function of cellulose in the plant cell wall?

Cellulose provides strength and structural support.

What organelle produces ATP through cellular respiration?

The mitochondrion.

What is ATP?

ATP (adenosine triphosphate) is the cell's primary usable energy molecule.

What is diffusion?

The movement of molecules from an area of higher concentration to an area of lower concentration.

What is osmosis?

The movement of water across a selectively permeable membrane.

In what direction does water move during osmosis?

Water moves toward the side with the higher solute concentration (lower free-water concentration).

Does water move into or out of cells placed in a hypotonic solution?

Into the cells.

Why does water move into a cell in a hypotonic solution?

The solution outside the cell has a lower solute concentration than the cell, so water moves into the cell by osmosis.

What type of solution causes crenation of red blood cells?

A hypertonic solution.

What happens to a red blood cell in a hypertonic solution?

Water leaves the cell, causing it to shrink or crenate.

What type of solution causes chloroplasts to be pushed outward against the cell wall?

A hypotonic solution.

If a solution has more hydrogen ions than hydroxide ions, where is it on the pH scale?

Below 7; it is acidic.

What does a pH below 7 indicate?

An acidic solution.

What does a pH of 7 indicate?

A neutral solution.

What does a pH above 7 indicate?

A basic/alkaline solution.

What helps maintain human blood at approximately pH 7.4?

Buffers.

What are buffers?

Substances that help resist changes in pH.

What structures are common to both prokaryotic and eukaryotic cells?

Plasma membrane, cytoplasm, DNA, and ribosomes.

What is the function of the nucleus?

It contains the cell's genetic material (DNA) and helps control cellular activities.

What is the function of ribosomes?

They carry out protein synthesis.

What is the function of the rough ER?

It is involved in protein synthesis and processing and has ribosomes attached to its surface.

What is the function of the smooth ER?

It is involved in lipid synthesis and carbohydrate metabolism and lacks ribosomes.

Which organelle would be abundant in cells that produce steroid hormones?

Smooth ER, because it is involved in lipid and steroid synthesis.

What is the function of the Golgi apparatus?

It processes, packages, and distributes proteins and lipids.

What is the function of vesicles?

They store and transport substances within the cell or to/from the cell membrane.

What is the function of lysosomes?

They contain digestive enzymes that break down macromolecules and worn-out cell parts.

What is the function of peroxisomes?

They contain enzymes involved in breaking down fatty acids and detoxifying substances such as hydrogen peroxide.

What is the function of the cytoskeleton?

It helps maintain cell shape and assists with movement of cell parts.

What is the function of centrioles?

They help organize microtubules, particularly during cell division, and are associated with the organization of cilia and flagella.

What are the three structures unique to plant cells emphasized in this lab?

Cell wall, large central vacuole, and chloroplasts.

What is the function of the plant cell wall?

It provides support, protection, and structural strength.

What is the function of the large central vacuole?

It stores water, nutrients, and waste products and helps maintain pressure within the plant cell.

What is the function of chloroplasts?

They carry out photosynthesis, producing sugars using light energy.

What is a hypotonic solution?

A solution with a lower solute concentration than the cell.

What happens to a cell in a hypotonic solution?

Water generally moves into the cell, which can cause the cell to swell.

What is a hypertonic solution?

A solution with a higher solute concentration than the cell.

What happens to a cell in a hypertonic solution?

Water generally moves out of the cell, causing it to shrink.

What is an isotonic solution?

A solution with approximately the same solute concentration as the cell.

What happens to a cell in an isotonic solution?

There is no net movement of water into or out of the cell.

What happens to a red blood cell in a hypotonic solution?

Water enters the cell, causing it to swell and potentially burst.

What happens to a red blood cell in a hypertonic solution?

Water leaves the cell, causing crenation/shrinking.

What happens to a red blood cell in an isotonic solution?

It maintains its normal shape because there is no net water movement.