Biology Chapter: Cell Transport and Organelles

Transport Across Cell Membranes

• Moving molecules against the concentration gradient is active transport.
• Active transport requires energy.
• Taking substances into the cell is endocytosis.
• Pinocytosis involves taking in water, phagocytosis involves taking in solids.
• Pushing substances out of the cell is exocytosis.
• Exocytosis is how waste is removed from cells.
• The sodium-potassium pump moves 3 sodium ions out of the cell for every 2 potassium ions moved in.

Organelles of Animal and Plant Cells

• The term organelle once referred to only membranous structures.
• All organelles in a cell function simultaneously.
• Organelles process incoming chemicals.

Prokaryotic Cells

• Many prokaryotes have small rings of DNA called plasmids.
• Prokaryotes have ribosomes for protein synthesis.
• Photosynthetic cyanobacteria have flattened disks called thylakoids which contain light-sensitive pigments.
• Prokaryotes display a wide variety of metabolic functions.
• Prokaryotes live in diverse environments.
• Prokaryotes can use almost any organic matter as a nutrient.
• Prokaryotes are more metabolically competent than human beings.
• Prokaryotes can synthesize any molecule they need given adequate nutrients.
• Humans use bacteria to produce products for human use.

Cell Theory

• Cells come from pre-existing cells.
• All organisms are made up of cells.
• Cells are the basic living units in all organisms.

Cell Size

• Cells are usually small.
• A frog’s egg is visible to the human eye.
• Micrometers are used to measure cells.
• Nanometers are used to measure cell inclusions and macromolecules.
• The surface area to volume ratio of cells is important for nutrient intake and waste removal.

Vacuoles

• Vacuoles are large membrane-bound sacs.
• Vacuoles are distinguished from vesicles by size.
• In plants, algae, and fungi, vacuoles perform many of the roles that lysosomes perform in animals.
• The central vacuole is usually a single large sac found in plant cells.
• Vacuoles store water, food, salts, pigments, and metabolic wastes;
• The vacuole maintains turgor pressure.
• The tonoplast is the membrane of the plant vacuole.
• Food vacuoles are found in protozoa and some animal cells.
• Contractile vacuoles remove excess water.

Microbodies

• Microbodies are small membrane-bound organelles.
• Microbodies carry out specific cellular functions.

The Cytoskeleton

• Actin filaments are thin fibers.
• Actin filaments form a network beneath the plasma membrane.
• Actin filaments are involved in forming pseudopods.
• Intermediate filaments are thicker than actin filaments but thinner than microtubules.
• Intermediate filaments support the nuclear envelope and the plasma membrane.
• Keratin is an intermediate filament that is important for the strength of skin cells.
• Intermediate filaments are dynamic structures.

Test your knowledge on cell transport mechanisms, including active transport, endocytosis, and exocytosis. Additionally, explore the characteristics and functionalities of animal and plant cell organelles, as well as prokaryotic cell structures. This quiz will challenge your understanding of cellular processes and organelle functions.