Cell structure and function Flashcards
What is the main difference between eukaryotes and prokaryotes?
Eukaryotes have membrane-bound organelles, including a nucleus, whereas prokaryotes do not.
Are viruses considered living organisms?
No, viruses are non-living. They require a host cell to replicate and do not perform independent life processes.
What are the four kingdoms within eukaryotes?
Animals, plants, fungi, and protists.
What is the Fluid Mosaic Model?
It describes the cell membrane as a bilayer of phospholipids with embedded proteins, where components can move laterally within the membrane.
What are the main components of the cell membrane?
Phospholipids, glycolipids, sterols (e.g., cholesterol), and proteins.
What are the three types of membrane proteins?
Integral, peripheral, and lipid-anchored proteins.
What is facilitated diffusion?
Passive transport along a concentration gradient requiring transport proteins, such as channels or carriers.
How does active transport differ from passive transport?
Active transport moves substances against their concentration gradient using energy, usually in the form of ATP.
What are examples of endocytosis?
Pinocytosis (cell drinking), phagocytosis (cell eating), and receptor-mediated endocytosis.
What is exocytosis?
The process where vesicles fuse with the plasma membrane to release contents outside the cell.
What is the function of the nucleus?
Houses the cell’s genetic material (DNA) and controls activities like transcription and replication.
How do rough and smooth endoplasmic reticulum (ER) differ?
Rough ER is studded with ribosomes and synthesizes proteins, while smooth ER is involved in lipid synthesis and detoxification.
What does the Golgi apparatus do?
Processes, packages, and distributes proteins and lipids for secretion or internal use.
What is the role of lysosomes?
Contain enzymes for intracellular digestion, including breaking down waste and pathogens.
What is the primary function of mitochondria?
They produce ATP through aerobic respiration and are involved in apoptosis (programmed cell death).
What is the cytoskeleton made of?
Microfilaments, intermediate filaments, and microtubules, which provide structure, movement, and intracellular transport.
What is cell differentiation?
The process by which cells become specialized to perform specific functions, often by activating or deactivating certain genes.
What are the different types of stem cell potencies?
Totipotent: Can form all cell types, including the placenta.
Pluripotent: Can form all cell types except the placenta.
Multipotent: Can form multiple cell types within a lineage.
Unipotent: Can form one type of cell.
What are three main types of blood cells?
Erythrocytes: Red blood cells that transport oxygen.
Leukocytes: White blood cells involved in immunity.
Platelets: Involved in clotting.
How are neurons specialized?
Neurons are adapted to transmit electrical signals and are the longest and oldest cells in the body.
What are the four main types of tissues?
Epithelial, connective, muscle, and nervous tissue.
What is the function of epithelial tissue?
Protects surfaces, lines cavities, and aids in absorption and secretion.
Where is connective tissue found?
In bone, cartilage, adipose tissue, blood, and other supportive structures.
What is the role of muscle tissue?
Contracts to produce movement and is categorized into skeletal, smooth, and cardiac muscle.
