Biology: Cells and Cell Metabolism

Study Notes

Cells

Cells are the fundamental units of life, characterized by a plasma membrane, cytoplasm, and genetic material.
Different cell types exhibit specialized structures and functions due to the expression of unique genes.
Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells possess both.
Specialized organelles within eukaryotic cells perform specific functions, such as energy production (mitochondria) and protein synthesis (ribosomes).
Cellular compartments are crucial for regulating biochemical processes and maintaining cellular homeostasis.
The cell membrane acts as a selective barrier, controlling the movement of substances in and out of the cell.
Cell membranes are selectively permeable, allowing specific molecules to pass while restricting others.

Cell Metabolism

Cell metabolism encompasses the sum of all chemical reactions within a cell to maintain life.
Two major types of metabolic pathways: catabolism (breakdown of molecules for energy release) and anabolism (synthesis of complex molecules).
Metabolic pathways are often interconnected, with intermediates in one pathway serving as substrates in another.
Energy currency of cells is ATP (adenosine triphosphate), storing and transferring energy for cellular processes.
Cellular respiration is a crucial metabolic pathway that breaks down glucose for ATP production.
Photosynthesis captures light energy to convert carbon dioxide and water into glucose, a process fundamental in many ecosystems.
Enzymes play a critical role in regulating metabolic reactions, lowering activation energy and speeding up the rate of reactions.
Many metabolic reactions are regulated by feedback mechanisms, where the product of a pathway inhibits its own synthesis or an upstream step, maintaining homeostasis.

Cell Division

Cell division is the process by which cells replicate, allowing for growth, repair, and reproduction.
Two main types of cell division: mitosis (for somatic cells) and meiosis (for gamete formation).
Mitosis results in two genetically identical daughter cells.
Meiosis results in four genetically unique daughter cells with half the number of chromosomes as the parent cell.
Each step of mitosis and meiosis involves carefully controlled processes of chromosome replication, separation, and partitioning.
Cell cycle regulation is crucial to prevent uncontrolled cell division, which can lead to cancer.
Checkpoints in the cell cycle ensure that cells only divide under appropriate conditions.
Cytokinesis is the division of the cytoplasm in cell division.

Enzyme Function

Enzymes are biological catalysts that speed up biochemical reactions without being consumed in the process.
Enzymes are highly specific, targeting particular substrates (reactants) for the reactions they catalyze.
The active site of an enzyme is a specific region where the substrate binds, facilitating the reaction.
Enzyme activity is influenced by various factors including temperature, pH, and substrate concentration.
Enzyme function is often regulated by allosteric effectors, which bind to sites other than the active site.
Competitive inhibition occurs when a molecule similar to the substrate binds to the active site, preventing the true substrate from binding.
Non-competitive inhibition occurs when a molecule binds to a site other than the active site, altering the enzyme's conformation and preventing substrate binding.
Enzyme activity can be controlled by covalent modification (e.g., phosphorylation).
Enzymes form complexes and participate in multistep metabolic pathways, regulating the flow of intermediates.

Description

Explore the fundamental concepts of cells and cell metabolism in this quiz. Learn about the differences between prokaryotic and eukaryotic cells, as well as the importance of cellular organelles and metabolic pathways. Test your knowledge on how cells function and maintain homeostasis.