Ch. 7- Inside the cell

• All cells have

  Proteins- do most cell functions

  Nucleic acids- store, transmit, process info

  Carbohydrates-provide chemical energy, carbon, support and identity

  Plasma membrane- selectively-permeable membrane barrier
• Prokaryotic cells have

  1 singular chromosome in nucleiod

  small circle DNA molecules called plasmids

  ribosomes

  cell wall

  unicellular
• Prokaryotes vs Eukaryotes (3 main differences)

  Eukaryotic cells are larger

  Eukaryotic chromosome are in a nucleus

  Eukaryotic cytoplasm is compartmentalized into larger number of distinct organelles
• More prokaryote vs eukaryote

  Prokaryotes are unicellular, Eukaryotes can be uni and multicellular

  Prokaryotes have fewer structures
• Unique plant identifier

  large central vacuole
• Places DNA can be found in a cell

  mostly nucleus, but also mitochondria and chloroplast
• The nucleus is the

  center for information storage (DNA) and processing

  Lighter areas have loosely packed sections of chromosomes

  Darker areas have densely packed sections of chromosomes
• Parts of the nucleus (3)

  Nuclear envelope- a double-membrane studded with pores

  Nuclear lamina- maintains nucleus shape

  Nucleolus- ribosomal RNA is synthesized, ribosome subunits are made
• Ribosomes

  make proteins, lack a membrane so not considered organelles

  some are free in cytosol,

  those attached to ER-manufacture proteins for excretion
• Endoplasmic Reticulum is an extension of the nuclear envelope that is involved in the synthesis and transport of lipids and proteins
• Rough ER

  has ribosomes

  in the lumen, proteins are folded and processed

  proteins made can carry messages to other cells, catalyze reactions or act as membrane transporters or pumps
• Smooth ER

  no ribosomes

  stores Ca+ ions

  has enzymes that catalyze reactions involving lipids that:

  can make lipids or modify lipids and other poisonous molecules
• Golgi Apparatus (delivery)

  series of stacked flat membranous sacs called cisternae

  process, sorts and ships proteins made by RER

  cis side- faces nucleus and receives products from RER

  trans side- faces plasma membrane and ships products out

  membranous vesicles carry materials to and from the organelle
• Lysosomes- lyses

  are only in animal cells

  recycling centers that digest macromolecules and export monomers to cytosol

  have about 40 different types of enzymes, work best at pH 5.0, proton pumps maintain low internal pH
• Lysosome tactics

  • Receptor-mediated endocytosis uses receptors to bind to macromolecules outside, vesicle delivers early endosome, acidifies and matures into late endosome
  • Phagocytosis- brings small cell/particle in through plasma membrane and forms phagosome, fuses with lysosome when delivered to it and gets digested
  • Autophagy- enclose damaged organelle (already inside cell) within a membrane and sent to lysosome for digestion. Lysosome releases small molecules from digested stuff into cytosol
• Vacuoles

  large and membrane- found in plants and fungi

  most are used to store water and ions, some are specialized for digestion

  In seeds filled with proteins, in flower petals have pigments

  may have noxious compounds to protect leaves and stems from being eaten
• Peroxisomes

  • happen when empty vesicles from ER are loaded with peroxisome specific enzymes from cytosol
  • have enzymes that oxidize ethanol in alcoholic beverages, oxidation usually makes hydrogen peroxide
  • Enzyme catalase detoxifies it
• Mitochondria

  supply ATP (energy) to cells

  have their own mitochondrial DNA (mtDNA)

  make their own ribosomes, and have cisternae
• Chloroplasts

  where photosynthesis happens, most plant and agal cells have it

  have their own DNA and make their own ribosome

  Stroma- inner fluid around thylakoids

  Thylakoids- circular disk in stacks that make sugar in photosynthesis to be broken down into ATP by mitochondria

  Granum- stack of disks
• Mitochondria and Chloroplasts both

  have a double membrane

  have free ribosomes and circular DNA molecule

  grow and reproduce somewhat independently

  ancestor eukaryotic cell- engulfed oxygen using non-photosynthetic prokaryote made mitochondria, engulfed photosynthetic prokaryote and made chloroplast
• Eukaryotic Cell Wall

  plants, algae, fungi have for structure and support

  rods/fibers of a carb run through stiff matrix of polysaccharides and proteins
• Size and number of organelles in cells correlate with cell's specialized function
• Lysosomes and centrosome are not in animal cells, only animal cells have centrioles