Cell Structure and Function Quiz

Cell Structure and Function

• Cells are the fundamental units of life, exhibiting diverse shapes and sizes tailored to their specific roles.
• Prokaryotic cells (bacteria, archaea) lack a membrane-bound nucleus and other organelles.
• Eukaryotic cells (plants, animals, fungi, protists) possess a nucleus and membrane-bound organelles, enabling compartmentalization of functions.
• Key organelles include the nucleus (managing cell activities), mitochondria (energy production), chloroplasts (photosynthesis in plants), endoplasmic reticulum (protein and lipid synthesis), Golgi apparatus (modifying, sorting, and packaging proteins), ribosomes (protein synthesis), vacuoles (storage).
• Cell membranes regulate the passage of substances into and out of cells through semi-permeable structures.
• Plant cells have a cell wall providing structural support.

Cell Transport

• Passive transport, requiring no energy, moves substances down their concentration gradient.
• Diffusion involves the movement of a substance from high to low concentration.
• Osmosis is the water movement across a selectively permeable membrane, from hypotonic (low solute) to hypertonic (high solute) solutions.
• Facilitated diffusion uses transport proteins to assist substance movement across the membrane.
• Active transport, using ATP, moves substances against their concentration gradient, from low to high concentration.

Photosynthesis

• Photosynthesis is the process where autotrophs convert light energy into chemical energy (glucose).
• This process occurs within chloroplasts, specifically the thylakoid membranes.
• Photosynthesis involves two stages: light-dependent reactions (capturing light energy) and light-independent reactions (Calvin cycle, producing glucose).
• Light-dependent reactions generate ATP and NADPH, fueling the light-independent reactions.
• Plants absorb carbon dioxide, incorporating it into glucose molecules during the Calvin cycle.

Respiration

• Cellular respiration is the breakdown of glucose to release energy in the form of ATP.
• Aerobic respiration, requiring oxygen, is the primary energy-producing pathway.
• Anaerobic respiration, without oxygen, yields less ATP compared to aerobic respiration.
• Cellular respiration involves three main stages: glycolysis (glucose splitting), Krebs cycle (further glucose breakdown), and electron transport chain (ATP production).
• Fermentation, such as lactic acid or alcoholic fermentation, is a type of anaerobic respiration.

Enzymes

• Enzymes are biological catalysts speeding up chemical reactions in living organisms.
• Enzymes are proteins with unique shapes, allowing for specific substrate binding.
• The active site of an enzyme is where the substrate binds.
• Enzyme activity is influenced by temperature, pH, and substrate concentration.
• Extreme temperatures and pH values can denature enzymes (disrupt their structure and function).

Genetics

• DNA, the genetic material, holds instructions for building proteins.
• Genes are DNA segments that code for specific proteins.
• DNA replication creates copies of DNA before cell division.
• Transcription produces RNA from DNA, carrying the genetic code to ribosomes.
• Translation converts RNA instructions into proteins at the ribosomes.
• Mutations are changes in the DNA sequence.

Biodiversity

• Biodiversity encompasses the variety of life on Earth, from genes to ecosystems.
• Biodiversity varies significantly across regions, mainly due to climate.
• Biodiversity offers both threats and benefits.
• Biodiversity includes species variety, ecosystem diversity, and genetic diversity within species.
• Species extinction is a natural process, but current extinction rates are elevated.

Ecology

• Ecology studies the interactions between organisms and their environment.
• Populations consist of individuals of the same species in a particular area.
• Communities comprise diverse populations interacting in an area.
• Ecosystems encompass interactions between populations, communities, and abiotic factors.
• Organisms interact through relationships such as competition, predation, and symbiosis (mutualism, commensalism, parasitism).

Test your knowledge on the fundamental units of life with this quiz on cell structure and function. Explore the differences between prokaryotic and eukaryotic cells, the various organelles, and their specific roles within the cell. Additionally, understand the mechanisms of cell transport and the importance of cell membranes.