Prokaryotic vs Eukaryotic Cells Quiz

Prokaryotic vs Eukaryotic Cells

• Prokaryotic cells evolved first, dominating Earth for over 1.5 billion years.
• Eukaryotic cells evolved from prokaryotic cells around 1.8 billion years ago.
• Prokaryotic cells are simpler and smaller than eukaryotic cells.
• Eukaryotic cells have a nucleus and other membrane-bound organelles.
• Both cell types have a plasma membrane, cytosol, chromosomes, and ribosomes.
• Prokaryotic cells do not have a nucleus or other membrane-bound organelles.

Prokaryotic Cell Structure

• DNA is coiled into a nucleoid region, not surrounded by a membrane.
• Prokaryotic ribosomes are smaller than eukaryotic ribosomes.
• Most have a rigid cell wall outside the plasma membrane.
• Some have a sticky capsule that helps them adhere to surfaces.
• Some have flagella for movement.
• May possess fimbriae for attachment.

Eukaryotic Cell Structure

• Organelles are membrane-bound compartments.
• Nucleus houses the cell's DNA, organized into chromosomes.
• Ribosomes are sites of protein synthesis, either free in cytoplasm or bound to the rough ER.
• Endoplasmic Reticulum (ER) produces proteins, lipids, and membrane components.
• Rough ER has ribosomes attached, for protein export.
• Smooth ER lacks ribosomes, synthesizes lipids and detoxifies substances.
• Golgi apparatus processes, sorts, and ships proteins or lipids.
• Lysosomes contain digestive enzymes.
• Vacuoles store and transport materials (central vacuole in plants, contractile vacuoles in protists).
• Mitochondria generate ATP; Chloroplasts, convert solar energy in plants/algae, are also part of the endomembrane system.
• Cytoskeleton provides structural support, movement, and internal organization, Composed of proteins.

Nucleus

• Contains the cell's genetic instructions (DNA).
• DNA is organized into chromosomes, visible during cell division.
• Nucleolus is a site of rRNA synthesis and ribosome production.
• Nuclear envelope controls passage of materials in and out of the nucleus (with pores).
• Chromatin is the complex of DNA and proteins when the cell isn't dividing.

Endomembrane System

• Connected network of membranes (nuclear envelope, ER, Golgi, lysosomes, vacuoles, and plasma membrane).
• Modifies, sorts, and ships proteins or lipids with further processing/packaging.
• Produces proteins, lipids, and membrane components.

Ribosomes

• Cellular protein factories, synthesize proteins, either free in cytoplasm or bound to the rough ER.
• Free ribosomes synthesize proteins for use in the cytosol, while bound ribosomes make proteins to be exported or incorporated into the endomembrane system.
• Ribosomes are structurally identical, but function differently depending on their location.

Mitochondria

• Generate ATP through cellular respiration.
• Have two membranes (outer and inner).
• Inner membrane has folds called cristae, increasing surface area for ATP synthesis.
• Contain their own DNA and ribosomes (evidence supporting the endosymbiotic theory).

Chloroplasts

• Carry out photosynthesis in plants and algae.
• Have two membranes (outer and inner).
• Thylakoids are the site of chlorophyll and light-capturing reactions, are stacked into grana.
• Stroma is the fluid surrounding the thylakoid sacs.
• Contain their own DNA and ribosomes (evidence supporting the endosymbiotic theory).

Lysosomes

• Membrane-bound organelles containing digestive enzymes.
• Break down and recycle damaged organelles, excess materials, or engulfed substances for cellular recycling.

Vacuoles

• Membrane-bound sacs for storage, transport, or elimination of materials.
• Central vacuole in plants stores water and maintains turgor pressure.
• Contractile vacuoles in protists regulate water content.

Peroxisomes

• Contain enzymes for detoxification of harmful substances (hydrogen peroxide).
• Important for various metabolic processes (lipid metabolism).

Other

• Cytoskeleton provides structural support, movement, and internal organization, composed of proteins.
• Cell walls provide support and protection (plant and fungi cells).
• Prokaryotic cells may have flagella for movement, fimbriae for attachment, and a capsule.
• Eukaryotic cells may have cilia or flagella for movement.