chapter 7

  • microscopy:

    • magnification

      • the ratio of an object’s image to its real size

    • resolution

      • the measure of the clarity of the image

    • contrast

      • visible differences in brightness between parts of the sample

  • light microscopes don’t show the organelles, so we use electron microscopes

    • SEMs TEMs

  • cell fractionation takes cells apart and separates the major organelles from one another

  • prokaryotes: protists, fungi, animals, and plants

    • no nucleus

    • DNA/RNA unbound in the nucleoid

    • no membrane bound organelles

    • cytoplasm

  • eukaryotes: bacteria and archaea

    • DNA in a nucleus

    • membrane bound organelles

    • bigger than prokaryotes

  • all cells have:

    • plasma membrane

    • semifluid substance (cytosol)

    • chromosomes / genetic information

    • ribosomes

  • the nucleus

    • nuclear envelope contains the nucleus

      • nuclear envelope is a double bilayer membrane

    • the nucleus has pores to regulate the exit and entry of stuff from the nucleus

    • the DNA is organized into chromosomes

      • chromosomes have dna and protein (chromatin)

      • chromatin forms discrete chromosomes by condensing

    • the nucleolus is where rRNA is synthesized

  • ribosomes

  • made of rRNA and protein

  • synthesize proteins

  • endomembrane system

    • nuclear envelope

    • endoplasmic reticulum

      • smooth

        • synthesizes lipids

        • metabolizes carbs

        • detoxification

        • calcium ion storage

      • rough (rough has ribosomes on the surface)

        • secretes glycoproteins

        • distributes transport vesicles

    • golgi apparatus

      • modification and sorting and packaging materials into transport vesicles

    • lysosome

      • sac of enzymes that digests macromolecules

      • acidic environment

    • vacuoles

      • food vacuoles

      • contractile vacuoles

        • pump excess water out of cells

      • central vacuoles

        • in plants

    • plasma membranes

  • mitochondria

    • site of cellular respiration

    • inner membrane called cristae

      • presents a large surface

    • matrix and intermembrane space

  • chloroplasts

    • site of photosynthesis

    • thylakoids stacked to form a granum

    • stroma is the fluid

    • chloroplast is a plastid

  • cytoskeleton

    • contains:

      • microtubules

        • the thickest

      • microfilaments

        • actin filaments

        • the thinnest

      • intermediate filaments

        • in the middle

    • interacts with motor proteins to produce cell motility

  • cell wall

    • primary cell wall

    • middle lamela

    • secondary cell wall

  • ECM

    • made up of glycoproteins

      • collagen, proteoglycans, fibronectin

  • junctions

    • plasmodesmata in plant cells

    • animal:

      • tight junctions

      • desmosomes

      • gap junctions