Cell Membranes

What is the purpose of a cell membrane?

The cell membrane functions as a protective barrier that regulates and maintains homeostasis by controlling the movement of substances in and out of the cell.

Fill in the Blank: The cell membrane is __________ permeable, allowing only some substances to pass through.

selectively

What type of transport requires energy (ATP) to move substances across the cell membrane?

Active transport is the process of moving molecules against their concentration gradient using energy in the form of ATP.

Fill in the Blank: Active transport requires __________ while passive transport does not.

energy (ATP)

What is the structural composition of the cell membrane?

The cell membrane is primarily composed of a phospholipid bilayer, which allows for fluidity and flexibility while providing a barrier against the external environment.

What are the two main types of cells?

The two main types of cells are Prokaryotic cells, which are simple and lack a nucleus, and Eukaryotic cells, which are more complex and contain a nucleus along with various organelles.

Fill in the Blank: Prokaryotic cells are __________ and lack major organelles.

primitive

What is a key characteristic of Eukaryotic cells?

A key characteristic of Eukaryotic cells is their organized structure, which includes a nucleus and various membrane-bound organelles that perform specific functions.

Fill in the Blank: DNA in Eukaryotic cells resides in the __________.

nucleus

What major organelle is absent in Prokaryotic cells?

The nucleus is a major organelle that is absent in Prokaryotic cells, which instead have their DNA freely located in the cytoplasm.

Fill in the Blank: Chlorophyll is not found in __________ in Prokaryotic cells.

chloroplasts

What is a key difference between Prokaryotic and Eukaryotic cells regarding DNA?

A significant difference is that in Eukaryotic cells, DNA is contained within a nucleus, providing added protection, whereas in Prokaryotic cells, DNA is found in the cytoplasm and is not enclosed.

Fill in the Blank: Eukaryotic cells have a __________ structure compared to Prokaryotic cells.

more organized

Name a type of transport that does not require energy.

Passive transport is a type of transport that allows substances to cross membranes without the use of energy, typically moving down their concentration gradient.

Fill in the Blank: All cells have a __________ that serves as a barrier and regulator for substances entering and leaving the cell.

cell membrane.