Models World of Cells

Prokaryotic Cell

A simple cell that lacks a nucleus and membrane-bound organelles

Organelles exclusive to animal cell

centrioles, lysosomes, and may have flagella.

Organelles exclusive to plant cell

cell wall, chloroplasts, and a central vacuole

Plant Cell

Contains a cell wall, chloroplasts, and a large central vacuole.

Animal Cell

Contains lysosomes, centrioles, and sometimes flagella; lacks a cell wall and chloroplasts.

Central Vacuole

Large storage sac in plant cells that stores water and maintains turgor pressure.

Chloroplast

Site of photosynthesis; converts light energy into chemical energy.

Cell Wall

Rigid outer layer that provides support and protection; found in plant cells.

Flagellum

Whip-like structure used for cell movement; found in some animal cells.

Centriole

organelle, Organizes microtubules and helps during cell division; found mainly in animal cells.

Lysosome

Contains digestive enzymes that break down waste and worn-out organelles

Mitochondrion

Produces ATP (energy) through cellular respiration

Golgi Apparatus

Modifies, sorts, packages, and ships proteins and lipids

Smooth Endoplasmic Reticulum (Smooth ER)

Produces lipids and detoxifies harmful substances.

Rough Endoplasmic Reticulum (Rough ER

Synthesizes and transports proteins; covered with ribosomes.

Ribosomes

Site of protein synthesis.

Nucleus

Contains DNA and controls cell activities.

Cytoskeleton

Network of fibers that provides support, shape, and movement

Plasma Membrane

Selectively controls what enters and leaves the cell.

Transmission Electron Micrograph (TEM)

Uses electrons to view internal cell structures in high detail.

Scanning Electron Micrograph (SEM)

Uses electrons to view detailed surface features of cells and organisms.

Light Micrograph (LM)

Uses visible light to view living cells.

Eukaryotic Cell

A more complex cell that contains a nucleus and membrane-bound organelles

Nucleoid Region

The area in a prokaryotic cell where DNA is found; it is not enclosed by a membrane

Nucleus

A membrane-bound organelle in eukaryotic cells that contains the cell's DNA

Organelles

Specialized structures within eukaryotic cells that perform specific functions

Main Difference Between Prokaryotes and Eukaryotes

Eukaryotes have a nucleus and membrane-bound organelles, while prokaryotes do not

Location of DNA in Prokaryotes

In the nucleoid region

Location of DNA in Eukaryotes

Inside the nucleus.

Membrane-Bound Organelles

Structures surrounded by membranes that carry out specific tasks; found in eukaryotic cells

Examples of Prokaryotes

Bacteria and Archaea

Examples of Eukaryotes

Animals, plants, fungi, and protists

Prokaryotic Cells Diameter

1-10 micrometers

Prokaryotic cells lack

nucleus, and membrane-bound organelles

Cell Wall

A rigid outer layer that provides shape, support, and protection to the prokaryotic and eukaryotic plant cell.

Plasma Membrane

A thin membrane just inside the cell wall that controls what enters and leaves the cell

DNA

The cell's genetic material that contains the instructions for cellular activities

Nucleoid Region

The area of a prokaryotic cell where the main DNA is located; it is not enclosed by a membrane

Plasmid

A small, circular piece of DNA separate from the main chromosome that often carries extra genes, such as antibiotic resistance genes

Typical Size of Prokaryotic Cells

1-10 μm (micrometers) in diameter

Ribosome

The structure responsible for protein synthesis (making proteins)

Where is DNA found in a prokaryotic cell?

In the nucleoid region

What structures surround a prokaryotic cell?

The cell wall and plasma membrane

What is the function of ribosomes

To produce proteins needed by the cell

What is the function of plasmids?

small DNA molecule, To carry additional genetic information that can provide advantages to the cell, most commonly found in prokaryotes

Prokaryotic cells organelles

cell wall, cell membrane, plasmid, DNA, ribosome

Magnification

The amount the image of an object is enlarged

Resolution

The ability of an optical instrument to show two objects as separate

Neutral lipid (fat)

Consists of 1 glycerol molecule and 3 fatty acids

Glycerol

The backbone molecule to which fatty acids attach in fats and phospholipids

Fatty Acid (FA)

Long hydrocarbon chain attached to glycerol

Phospholipid

A changed glycerol molecule with 2 fatty acids and 1 phosphate group

Phosphate Group

The polar part of a phospholipid that forms the head

Function of Phospholipids

Main component of cell membranes

Phospholipid Head

Hydrophilic because it contains the phosphate group.

Phospholipid Tails

Hydrophobic because they are fatty acid chains.

Cell Membrane Structure

Phospholipid bilayer.

Where to phospholipid heads face

outside the cell, hydrophilic region

where do phospholipid tails face

inside the cell, hydrophobic region

All Single Bonds in Fatty Acid Chain

Saturated fat

One or More Double Bonds in Fatty Acid Chain

Unsaturated fat

Surface Area Formula

Proportional to d²

Volume Formula

Proportional to d³

Why Do Small Cells Exchange Materials Faster?

They have a larger surface area-to-volume ratio.

What Enters Cells?

Oxygen (O₂) and glucose.

What Leaves Cells?

Carbon dioxide (CO₂).

Effect of Increasing Cell Size on Surface Area-to-Volume Ratio

The ratio decreases

Why Can't Cells Grow Indefinitely?

Volume increases faster than surface area, making material exchange less efficient.