Organelle structures

• What surrounds the nucleus?

  A double membrane called the nuclear envelope
• What is contained within the nucleoplasm?

  Chromatin (DNA and associated proteins)
• What is the function of the nucleolus?

  Assembly of ribosomes
• What surrounds mitochondria?

  A double membrane
• What is the purpose of the inner membrane folds in mitochondria?

  To increase surface area for ATP production
• What is found inside the mitochondrial matrix?

  Enzymes, mitochondrial DNA, and ribosomes
• What characterizes the Rough Endoplasmic Reticulum (RER)?

  Studded with ribosomes
• How does the Smooth Endoplasmic Reticulum (SER) differ from the RER?

  SER lacks ribosomes, giving it a smooth appearance
• What is the structure of the Golgi Apparatus?

  A stack of flattened, membrane-bound sacs
• What do lysosomes contain?

  Digestive enzymes (hydrolytic enzymes)
• What are ribosomes composed of?

  Two subunits made of rRNA and proteins
• Where can ribosomes be found in eukaryotic cells?

  Free in cytoplasm or attached to RER
• What is the size of ribosomes in eukaryotes?

  80S
• What surrounds chloroplasts?

  A double membrane
• What are thylakoids in chloroplasts?

  Stacks connected by lamellae containing chlorophyll
• What is contained in the stroma of chloroplasts?

  Enzymes, chloroplast DNA, and ribosomes
• What is the function of chlorophyll in chloroplasts?

  To capture light for photosynthesis
• What is the structure of a vacuole in plants?

  A large, membrane-bound sac
• What is the tonoplast?

  The membrane surrounding the vacuole
• What is the cell wall made of in plants?

  Cellulose fibers embedded in polysaccharides
• What is the composition of the cell wall in fungi?

  Made of chitin
• What is the structure of the cell wall in prokaryotes?

  Made of peptidoglycan
• What are centrioles made of?

  Microtubules arranged in a 9+0 pattern
• Where are centrioles usually found?

  In pairs at right angles near the nucleus
• What is the cytoskeleton composed of?

  A network of protein fibers
• What are microfilaments involved in?

  Cell shape and movement
• What do microtubules provide for the cell?

  Structural support and intracellular transport
• What is the plasma membrane made of?

  A phospholipid bilayer with embedded proteins
• What does selectively permeable mean in relation to the plasma membrane?

  It allows certain substances to pass through
• What do peroxisomes contain?

  Enzymes like catalase
• What is the function of catalase in peroxisomes?

  To break down hydrogen peroxide