Exam 1 Study Terms - Cell Biology

Vocabulary flashcards covering cell organelles, membrane transport, cytoskeletal structures, and gradients based on Exam 1 study notes.

Nucleus

The control center for the living cell; houses DNA.

Nuclear Envelope

The double membrane of the nucleus.

Nucleolus

Houses the RNA for making ribosomes (ribosomal RNA).

Chromatin

A mixture of DNA and proteins that are housed in a cell's nucleus; they form compact strands that fit inside.

Mitochondria

Organelles that generate chemical energy called ATP to power a cell's reactions.

Rough Endoplasmic Reticulum (ER)

Embedded with ribosomes that undergo protein synthesis.

Ribosomes

Perform protein synthesis (make proteins).

Golgi Apparatus

Modifies and packages proteins sent from the Rough ER.

Smooth Endoplasmic Reticulum (ER)

The organelle responsible for making lipids.

Centrosome

Acts as the main microtubule organizing center.

Lysosomes

Vacuoles containing destructive enzymes; digest macromolecules and break down dead / dying organelles.

Peroxisomes

Small, membrane-bound organelles responsible for breaking down fatty acids and dangerous toxins; produce hydrogen dioxide and water from neutralizations.

Cytoskeleton

A network of protein fibers that spread across all organelles in the cytoplasm; also used as tracks for transportation.

Microfilaments

The thinnest part of a cell's cytoskeleton made of actin; responsible for cell shape and movement, serving as tracks for motor proteins.

Microtubule

Small, hollow tubes that serve as part of a cell's internal skeleton.

Intermediate Filaments

The only cytoskeletal fiber not associated with motion; used to anchor organelles, especially the nucleus.

Plasma / Cellular Membrane

A flexible barrier that covers the cell and controls what enters and exits.

Phospholipid Bilayer

The semipermeable (selectively permeable) membrane that determines what can enter/exit the cell, composed of hydrophilic heads (B) and hydrophobic tails (A).

Active Transport

The process of moving molecules through the phospholipid bilayer using ATP.

Passive Transport

The process of moving molecules through the phospholipid bilayer; includes the diffusion category.

Facilitated Diffusion

Moves molecules across the cell membrane with the help of transport proteins (no ATP energy needed).

Simple Diffusion

Moves molecules across the cell membrane without the help of a transport protein (no ATP energy needed).

Exocytosis

Active transport process that uses a transport vesicle that fuses with the cell membrane; moves large waste particles or molecules out.

Endocytosis

The cell surrounds and engulfs larger particles or molecules with the cell membrane to bring them in.

Peripheral Proteins

Proteins attached to the surface of the membrane.

Free Proteins

Proteins that are not bound by a membrane.

Integral Proteins (Transmembrane)

Proteins embedded in the membrane.

Carrier Proteins

Proteins that change shape to move molecules and ions across the cell membrane.

Channel Proteins

A passageway embedded in the phospholipid bilayer that allows molecules to go down (follow) their concentration gradients.

Aquaporin

A specific type of channel protein used for transporting water molecules.

Glycoproteins

Proteins with carbohydrates attached for recognition.

Glycolipids

Lipids on the outer membrane to help cells recognize each other.

Osmosis

The movement of water molecules from an area of low solute concentration to an area with high solute concentration.

Solute

A substance that dissolves in a solvent to make a solution.

Hypertonic

More solute inside the cell (less water); cell shrivels as water exits.

Hypotonic

More water outside of the cell (less solute); cell expands and pops as water enters.

Isotonic

Equal amount of solute in both solutions; cell remains the same.

Chemical Gradient

The difference in concentration of a chemical substance in two areas.

Electrical Gradient

A difference in electrical charge between two areas.

Electrochemical Gradient

The combined force of a chemical concentration difference and an electrical charge difference; drives movement of ions.

Eukaryotic Cell Structure

A complex cell type containing membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, and Golgi apparatus.

Cell Wall

A rigid layer present in plant cells made of cellulose fibers.

Central Vacuole

A large vacuole filled with water and components created by the cell that creates internal pressure inside plant cells (helps them keep their shape).

Chloroplasts

Organelles in plant cells that perform photosynthesis to provide additional energy to the cell.

Centriole

The components of a centrosome in animal cells that are made of microtubules.