General Biology 1 - Cell Theory, Structure, and Energy Transformation (Flashcards)

A comprehensive set of Q&A flashcards covering cell theory, cell structure, organelles, transport, energy transformation, and plant/animal cell differences based on the provided notes.

What are the three postulates of the Cell Theory?

1) The cell is the basic unit of life; 2) All living organisms are composed of cells; 3) New cells are produced from pre-existing cells.

Who first named the cell after observing cork?

Robert Hooke.

What term did Anton van Leeuwenhoek use for the moving organisms he observed?

Animalcules.

What does Omnis cellula e cellula mean in the Cell Theory?

Cells come from pre-existing cells.

What is the key difference between prokaryotic and eukaryotic cells?

Prokaryotes lack a nucleus and membrane-bound organelles; eukaryotes have a nucleus and membrane-bound organelles.

What is the main function of the plasma membrane?

To enclose the cell, protect organelles, and regulate transport and communication.

What does the Fluid Mosaic Model describe?

A dynamic membrane consisting of phospholipids, cholesterol, and proteins that move laterally within the bilayer.

Name three main components of the plasma membrane.

Phospholipids, cholesterol, and proteins (including glycoproteins and glycolipids).

What are aquaporins?

Water channel proteins in the plasma membrane.

What is the cytoplasm?

The region between the plasma membrane and the nuclear envelope that contains cytosol and organelles.

What is cytosol and approximately how much of the cell does it comprise?

A gel-like fluid; about 70% of cellular content.

What are the main components of the nucleus and their roles?

The nucleus is the control center; it contains chromosomes; the nucleolus synthesizes ribosomes; the nuclear envelope with pores surrounds it.

What is the endomembrane system?

A group of connected membranes and organelles (ER, Golgi, lysosomes, vesicles, vacuoles, peroxisomes, centrosomes) that modify, package, and transport lipids and proteins.

What is the difference between rough ER and smooth ER?

Rough ER has ribosomes on its surface and synthesizes membrane and secreted proteins; smooth ER lacks ribosomes and synthesizes lipids and detoxifies.

What is the function of the Golgi apparatus?

To modify, sort, and package molecules from the ER; it has a cis (receiving) face and a trans (shipping) face.

What are ribosomes and where are they located?

Ribosomes are the sites of protein synthesis; present in both prokaryotes and eukaryotes; can be free-floating or attached to the rough ER.

What are lysosomes?

Digestive organelles that break down cellular wastes and enable recycling; also called the cell’s 'suicide bags' due to autophagy.

What are vacuoles and what is notable about plant cells?

Fluid-filled vesicles that store water and chemicals; plants typically have a large central vacuole.

What are peroxisomes?

Small, single-membrane organelles that break down fatty acids and detoxify toxins, protecting the cell from reactive oxygen species.

What are mitochondria and what do they do?

Powerhouses of the cell; generate ATP via cellular respiration; contain their own DNA and ribosomes.

What is ATP and how is energy released?

Adenosine triphosphate; energy is released when a phosphate group is hydrolyzed, forming ADP and releasing energy.

What are chloroplasts and what is their function?

Sites of photosynthesis; convert light energy to chemical energy; contain thylakoids and stroma.

Describe the structure of chloroplast membranes.

Chloroplasts have outer and inner membranes plus a thylakoid system; space between membranes is the intermembrane space; the fluid surrounding the thylakoids is the stroma.

What are thylakoids and granum?

Thylakoids are membrane-bound sacs; a granum is a stack of thylakoids where the light reactions occur.

What is the function of the chloroplast thylakoid system?

Sites for the light-dependent reactions of photosynthesis, where chlorophyll is located.

What is the role of cristae in mitochondria?

Cristae are folds of the inner mitochondrial membrane that increase surface area for metabolism.

What is a mitochondrion’s matrix and intermembrane space?

Matrix is the innermost fluid-filled space; intermembrane space is between the inner and outer membranes.

What is the difference between plant and animal cells?

Plant cells have cell walls, chloroplasts, and a large central vacuole; animal cells lack cell walls and chloroplasts and have smaller vacuoles.

What are centrosomes and centrioles responsible for?

Organize spindle fibers during cell division and help form the cytoskeleton.

What are chromatin and the nucleolus?

Chromatin is DNA–protein complex that condenses into chromosomes during cell division; the nucleolus is the site of ribosome synthesis.

What is the nucleus’s nuclear envelope and its pores function?

The nuclear envelope encloses the nucleus; nuclear pores regulate traffic between the nucleus and cytoplasm.

What is the rough endoplasmic reticulum’s role?

Ribosomes on its surface synthesize membrane proteins and proteins for export; these proteins are threaded into the ER lumen for modification and transport.

What is the smooth endoplasmic reticulum’s role?

Synthesis of lipids and phospholipids; detoxification and processing of proteins for membranes.

What are the roles of lysosomes versus vacuoles?

Lysosomes digest cellular waste and recycle components; vacuoles store water and chemicals and help maintain turgor in plants.

What is the Golgi apparatus’s cis face versus trans face?

Cis face receives; trans face ships modified proteins to their destinations.

What are the major components of the plasma membrane?

Phospholipid bilayer with hydrophilic heads and hydrophobic tails, cholesterol, and proteins (including channels and receptors); glycoproteins and glycolipids are carbohydrate-bearing proteins/lipids.

What are glycoproteins and glycolipids?

Proteins or lipids with carbohydrate attached; involved in cell recognition and signaling.

What is the role of the cytoskeleton in a cell?

Maintains cell shape and enables movement; helps position and move organelles.

What is the function of aquaporins?

Water channel proteins that facilitate rapid water movement across the membrane.

Why are cells generally small in size?

To maximize surface area-to-volume ratio, enabling efficient exchange of nutrients and wastes with the environment.

What are the two major stages of the cell cycle mentioned?

Mitosis and meiosis.

Name the four transport mechanisms across the plasma membrane listed in the notes.

Simple diffusion, facilitated diffusion, active transport, and bulk/vesicular transport.

What is the energy currency of the cell?

ATP (adenosine triphosphate).

Where does cellular respiration occur and what is produced?

Mitochondria; it produces ATP by extracting energy from sugars, fats, and other fuels.

Where do the light reactions of photosynthesis occur in chloroplasts?

In the thylakoid membranes of the chloroplast.

What is the difference between chromatin and chromosomes during cell division?

Chromatin is the relaxed DNA-protein complex; it condenses to form chromosomes during cell division.

What is the nucleolus mainly responsible for?

Ribosome synthesis.