Hnrs. Biology Cell Structure and Function: Key Organelles and Theories

What surrounds the nucleus and separates it from the cytoplasm?

The nuclear envelope

What is the structure of chromosomes during cell division?

Chromosomes are in a rod-like form.

What are the three molecules that are part of an animal cell membrane?

Phospholipids, cholesterol, and proteins.

Define selectively permeable.

A property that allows some substances to pass through while blocking others.

What is the function of the plasma (cell) membrane?

It separates the cell from its external environment and controls what enters and leaves the cell.

What is the role of lysosomes in a cell?

They contain digestive enzymes that break down macromolecules and recycle worn-out organelles.

What is the function of a vacuole?

It stores water, salts, and other substances.

What is cytosol?

The liquid inside the cell where organelles are suspended.

What are ribosomes made of?

RNA and protein.

What is the function of the rough endoplasmic reticulum (RER)?

It modifies proteins and is studded with ribosomes.

What is the function of the smooth endoplasmic reticulum (SER)?

It synthesizes lipids and detoxifies certain chemicals.

What does the Golgi apparatus do?

It sorts and packages proteins and other materials for transport.

Trace the pathway a protein takes to be secreted from the cell.

Ribosome → Rough ER → Vesicle → Golgi apparatus → Vesicle → Cell membrane.

What is the difference between free and attached ribosomes?

Free ribosomes make proteins in the cytosol, while attached ribosomes are bound to the RER or nuclear envelope.

What are microtubules and their function?

Hollow structures made of tubulin proteins that guide movement and separate chromosomes during cell division.

What are microfilaments and their role?

Thread-like structures made of actin that support the cell and help in cell movement.

What is the function of cilia?

They move materials over the surface of a cell and are short and numerous.

What is the function of flagella?

They enable cells to swim through liquids and are long and few.

What is the role of mitochondria?

They perform cellular respiration and produce ATP, the energy currency of the cell.

What is the function of chloroplasts?

They conduct photosynthesis in plants and algae.

What is the chemical equation for cellular respiration?

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP.

According to the serial endosymbiosis theory, which two organelles were once independent prokaryotes?

Mitochondria and chloroplasts.

What are the three parts of the cell theory?

1. All living things are made of cells. 2. Cells are the basic units of structure and function in living things. 3. New cells are produced from preexisting cells.

What are four characteristics common to both prokaryotic and eukaryotic cells?

Both have a cell membrane, cytosol, DNA, and ribosomes.

What is one example of a prokaryote?

Bacteria.

Name four examples of eukaryotes.

Fungi, animals, plants, and unicellular protists.

Identify three cell parts found in plant cells but not in animal cells.

Chloroplasts, cell wall, and central vacuole.

What is one cell part found in animal cells but not in plant cells?

Lysosomes.

What is the function of the nucleolus?

It is located inside the nucleus and makes ribosomes.

What is chromatin?

The thread-like form of DNA found in the nucleus.

What do nuclear pores do?

They control the entry and exit of substances into and out of the nucleus.