Cheat Sheet 2: Cells and Organelles Overview

What is the function of the nucleus in a cell?

Contains the cell's DNA and coordinates cell activities such as protein synthesis and reproduction.

What is the role of the rough endoplasmic reticulum?

Has ribosomes attached and functions to synthesize and store proteins.

What is the primary function of the cytoskeleton?

Provides mechanical support and helps bind adjacent cells.

What does the smooth endoplasmic reticulum synthesize?

Lipids and steroid hormones for export.

What is the function of the nucleolus?

Site of ribosome (rRNA) synthesis.

What is the role of the Golgi apparatus?

Modifies and packages proteins, including glycosylation of polypeptides.

What are mitochondria known for?

Making ATP, functioning in apoptosis, and breaking down nutrients, bacteria, and cell debris.

What are lysosomes responsible for?

Breaking down substances within the cell.

What is the composition of ribosomes in prokaryotes?

50S + 30S = 70S.

What are the key traits of prokaryotes?

No nucleus, single circular naked double-stranded DNA, ribosomes, cell walls made of peptidoglycan, and flagella constructed from flagellin.

What is the function of peroxisomes?

Breakdown of fatty acids and detoxification.

How do passive transport mechanisms function?

They move substances down their concentration gradient without using ATP.

What is the role of cholesterol in the cell membrane?

Regulates the fluidity of the cell membrane.

What is the difference between hypertonic, hypotonic, and isotonic solutions?

Hypertonic: higher solute concentration;

Hypotonic: lower solute concentration;

Isotonic: equal solute concentration.

What are channel proteins?

Proteins that allow specific ions and small molecules to pass through the membrane.

What is the function of carrier proteins?

Change shape after binding to specific molecules to transport them across the membrane.

What is endocytosis?

The process by which cells internalize substances by engulfing them.

What are the types of endocytosis?

Phagocytosis (solid material), pinocytosis (liquid material), and receptor-mediated endocytosis.

What are anchoring junctions?

Structures that connect two cells together, including desmosomes.

What is a tight junction?

Encircles each cell, producing a seal that prevents the passage of materials between cells.

What is a gap junction?

Narrow tunnels between animal cells that allow passage of ions and small molecules.

What are transport proteins?

Proteins that can use ATP to transport materials across the membrane.

What is the function of microtubules?

Support the cell and facilitate mobility for cell activities.

What are microfilaments composed of?

Actin, used for cell motility.

What is the role of intermediate filaments?

Maintain cell shape.