Cell Biology Overview Quiz

Cell Theory

• States all organisms consist of cells, which are capable of self-reproduction.
• Cells arise only from preexisting cells, emphasizing their role in biological processes.

Plasma Membrane

• Composed of a phospholipid bilayer embedded with proteins, regulating molecular traffic.
• Serves as a protective boundary between a cell's internal contents and the external environment.

Cytoplasm

• The aqueous region within a cell, situated between the nucleus/nucleoid and the plasma membrane.
• Contains various organelles suspended in the cytosol.

Cell Wall

• Provides structural protection particularly in bacteria, giving shape and rigidity.
• Composed primarily of peptidoglycan, distinguishing bacterial cells from eukaryotic cells.

Eukaryotic Cell

• Characterized by a membrane-bound nucleus and membranous organelles, facilitating greater complexity in functions.

Eukaryotic vs. Prokaryotic Cells

• Eukaryotic cells feature a nucleus, unlike prokaryotic cells, which have no such compartmentalization.
• Eukaryotes also possess a diverse assortment of organelles enabling specialized functions.

Animal and Plant Cells

• Both cell types contain mitochondria, the powerhouse of the cell.
• Plant cells uniquely feature chloroplasts for photosynthesis, enabling them to convert sunlight into energy.

Nucleus

• The most prominent organelle in eukaryotic cells, housing genetic material (DNA).
• Functions as the control center for cellular activities and gene expression.

Chromatin

• A structure composed of DNA strands and proteins within the nucleus, playing a role in packaging DNA.
• Condenses to form chromosomes during cell division.

Ribosomes

• Sites for protein synthesis, translating messenger RNA (mRNA) into polypeptide chains.
• Composed of ribosomal RNA and proteins, crucial for cellular growth and function.

Golgi Apparatus

• Modifies, sorts, and packages lipids and proteins received from the endoplasmic reticulum (ER) into vesicles.
• Involved in lysosome formation, which contain enzymes for intracellular digestion.

Lysosomes

• Membrane-bound vesicles containing hydrolytic enzymes, breaking down macromolecules and bacteria.
• Often referred to as the cell’s waste disposal system.

Vacuoles

• Larger in plant cells, these organelles store substances such as water, salts, sugars, and pigments.
• Help maintain turgor pressure against the cell wall in plant cells.

Chloroplasts

• Organelles that capture sunlight to synthesize carbohydrates through photosynthesis.
• Contain thylakoids where light reactions occur.

Mitochondria

• Membrane-enclosed organelles responsible for producing ATP through cellular respiration.
• Often called the "powerhouse of the cell."

Thylakoids

• Flat sac-like membranes within chloroplasts, essential for the light-dependent reactions of photosynthesis.
• Contain chlorophyll, the pigment crucial for capturing solar energy.

Grana

• Stacks of thylakoids, increasing the efficiency of light absorption for photosynthesis.
• Located within chloroplasts, these structures house chlorophyll.

Chlorophyll

• A green pigment situated in the thylakoid membranes, essential for photosynthesis.
• Captures solar energy, enabling the synthesis of carbohydrates.

Actin Filament

• A type of cytoskeletal filament, integral to cell movement and the transport of organelles within the cell.
• Plays a key role in maintaining cell shape and motility.