Goal 2 - The Cell Notes
CELL BOUNDARIES
Plasma Membrane
Cell Wall
Plasma Membrane
- Cell boundary.
- Selects what resources the cell needs and provides them through selective permeability.
- Very flexible.
Cell Wall
- Found only in plant cells, fungi, bacteria and some protists.
- Additional boundary located outside the plasma membrane.
- Rigid – provides structure and support, made of cellulose.
- Very porous allows all molecules in, NOT selectively permeable!
CELL CONTROL
Nucleus
ORGANELLES AND CELL ASSEMBLY
STORAGE
CELL ENERGY
CELL SUPPORT
LOCOMOTION AND FEEDING
Nucleus
- The boss of the cell.
- Contains genetic material and the directions to make the proteins needed by every part of the cell.
- Controls the activity of the organelles.
- Chromatin - located in the nucleus it has the master set of directions.
- Strands of DNA.
- Nucleolus – organelle within the nucleus that contains RNA and make ribosomes.
- Ribosomes- sites where the cell produces proteins according to the directions from the DNA.
- Not bound by a membrane.
- Made of RNA and protein.
- Must leave the nucleus in order for proteins to be made.
- Nuclear Envelope – a structure that separates the nucleus from the cytoplasm.
- Double membrane of 2 phospholipid bilayers containing small pores for substances (ribosomes and translated RNA) to pass through.
ORGANELLES AND CELL ASSEMBLY
- Cytoplasm – clear gelatinous fluid inside the cell. Suspends “holds” the organelles.
- Endoplasmic reticulum (ER) – the site of all cellular chemical reactions (helps with cell communication).
- Arranged in a highly folded membrane.
- Looks like an accordion.
- Rough Endoplasmic reticulum (ER) – Have ribosomes attached to them where they carry out the process of protein synthesis (“make the proteins”).
- Ribosomes – Located on ER or may float freely in the cytoplasm and make proteins.
- Smooth Endoplasmic reticulum (ER) – No ribosomes. They produce and store lipids.
- Golgi Apparatus. They are a flatted sack of tubular membranes.
- After proteins are made they are transferred to the Golgi where the proteins are sorted into packages.
- The Golgi Apparatus packs proteins into a membrane bound structure called a vesicle (like the mail or UPS).
- Packaging center – packages material for export.
- Vesicles – transport the proteins to the appropriate destination.
STORAGE
- Vacuole – membrane bound organelle used to temporarily store food, enzymes, or anything else needed by cell.
- Some store waste.
- Plants have a large vacuole, animal vacuoles, if present, are very small.
- Lysome – membrane bound organelles that have digestive enzymes.
- They digest worn out organelles, food particles, viruses, and bacteria.
- Membrane keeps the digestive enzymes from getting out and destroying the cell.
- They can fuse with the vacuole and disperse their enzymes into the vacuole to digest its contents.
- Suicide bag.
CELL ENERGY
- Chloroplasts – cell organelle that takes light, carbon dioxide, and oxygen to make glucose.
- Double membrane, outer membrane and a folded inner membrane (thylakoid membrane) where the energy from the sunlight is trapped in sacs called grana.
- Involved with photosynthesis.
- Contain chlorophyll (green pigment), which helps trap the light energy and gives plants their green color.
- Mitochondria – membrane bound organelle in plant and animal cells produces energy from glucose and oxygen.
- Composed of an outer membrane and a highly folded inner membrane.
- Energy is stored and can be accessed by other organelles.
- The powerhouse.
CELL SUPPORT
- Cytoskeleton – Cell support system.
- Framework for cells.
- Keeps shape of cell and helps to support the organelles.
- Thin hollow cylinders made of proteins and microfilaments.
- Centrioles – Only found in animal cells.
- Occur in pairs.
- Used during cell division.
LOCOMOTION AND FEEDING
- Cilia- short, look like hairs.
- Motion similar to a rowboat.
- Flagella – longer more whip-like motion.
- Usually 1 or 2.
- Unicellular form of locomotion.