Cells
How water will move if a cell is placed in an hypotonic solution
Water enters the cell causing it to swell up and possibly burst (In plants there is a gain of turgor pressure)
Carbohydrates in membrane
help to keep the membrane fluid consistent
Consider cell features that may be abundant/absent in certain cells based on their functions
- Cells that function in locomotion have high amounts of mitochondria and smaller amounts of smooth ER, rough ER, and Golgi bodies. - Cells that function to synthesize and excrete proteins have large amounts of Smooth ER, Rough ER, and Golgi bodies with a moderate amount of mitochondria. -Cells that function for protection/support will have high amounts of cytoskeleton and low amounts of smooth ER, rough ER, mitochondria, and Golgi bodies
Golgi Body
-can think of it as a warehouse for receiving, sorting, and shipping although some manufacturing does occur
How internal membranes and organelles contribute to cell functions
Membrane and membrane-bound organelles in eukaryotic cells compartmentalize intracellular metabolic processes and specific enzyme reactions. Each compartment or membrane-bound organelle localizes reactions, including energy transformation in mitochondria and production of proteins in RER. 1. RNA leaves the nucleus and is sent to ribosomes on the RER to form proteins which will be translated inside of the RER. 2. The membrane of the RER will start to surround the protein and then put the protein into a vesicle. 3. The protein is sent to the Golgi body to be packaged and shipped out of the cell through exocytosis. *Proteins that will remain inside the cell are translated through ribosomes in the cytosol.
How water will move if a cell is placed in an isotonic solution
The exchange of water molecules in and out of the cell would be equal and the cell would remain the same size
Water potential
The higher the potential of water, the more likely the water is to flow into lower water potential areas. More pressure increases potential. More solute lowers water potential
Phospholipids in membrane
These form bilayers which act as barriers that prevent charged particles and large molecules from moving across them
Proteins in membrane
These have many roles in the cell membrane such as transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, and attachment of the cytoskeleton
How water will move if a cell is placed in an hypertonic solution
Water inside the cell moves out of the cell, causing the cell to shrink. (In plants there is a loss of turgor pressure)
How different cell types show differences in subcellular components
-Animal cells have: lysosomes, centrioles, and flagella -Plant cells have: chloroplasts, central vacuole, cell wall, and plasmodesmata
Vacuoles
-large vesicles derived from the endoplasmic reticulum and golgi apparatus used for storage.
Cytoskeleton
-network of fibers extending throughout cytoplasm. Gives mechanical support to the cell and maintains cell's shape.
Mitochondria
-organelle that converts energy to forms that cells can use for work (they are the powerhouse of the cell).
Cytoplasm
-thick, jelly-like material that supports and protects cell organelles.
Key ways in which prokaryotes differ from eukaryotes with respect to genome, membrane-bound organelles, size and reproduction.
1. A cell's genetic information is called its genome. A prokaryotic genome is often a single DNA molecule whereas eukaryotic genomes usually consist of a number of DNA molecules. 2. Eukaryotic cells have membrane-bound organelles. Prokaryotic cells do not have membrane-bound organelles. 3. Eukaryotic cells are generally much larger than prokaryotic cells. 4. Prokaryotic cells reproduce by binary fission. Eukaryotic cells reproduce by mitosis to form somatic cells or by meiosis to form gametes.
Basic differences between prokaryotic and eukaryotic cells
1. In a eukaryotic cell, most of the DNA is in the nucleus, which is bounded by a double membrane. In a prokaryotic cell, the DNA is concentrated in the nucleoid, a region which is not bounded by a membrane. 2.Eukaryotic cells examples: plants and animals. Prokaryotic cells example: bacteria 3.Eukaryotic cells have membrane-bound organelles. Prokaryotic cells do not have membrane-bound organelles.
How cell size and shape affect the overall rate of nutrient intake and waste elimination
-The volume determines how much enters and leaves the cell while surface area determines the rate at which nutrients are taken in or out. -The smaller the cell, the more favorable of a surface area to volume ratio because the exchange of materials with the environment is done through diffusion. -As a cell grows, its demand for material resources increases because more cellular structures are necessary to exchange materials and energy with the environment. - Volume increases faster than surface area so the rate of nutrients are able to be taken in and waste taken out is not fast enough to accommodate the size of the cell, so the cell divides.
Ribosomes
-complexes made of ribosomal RNA and proteins. They are the cellular components that carry out protein synthesis.
Nucleus
-contains most of the genes in the eukaryotic cell. DNA is organized in discrete units called chromosomes (structures carrying genetic information).
Cell Membrane
-encloses the cell and regulates what comes in or goes out
Endoplasmic Reticulum, Rough ER, Smooth ER
-extensive network of membranes that carries materials through the cell. -Rough ER has outer surface studded with ribosomes and makes proteins. -Smooth ER has outer surface lacking ribosomes and functions synthesis of lipids, metabolism of carbohydrates, detoxification of drugs/poisons, and storage of calcium ions.
Be able to predict and justify how a change in an organelle would affect the function of that cell or organism
Different types of cells have different amounts of some organelles. For example, muscle cells that need a lot of energy have large numbers of mitochondria
The structure and function of organelles found only in plant cells or only in animal cells
In animal cells but not plant cells: -Lysosomes: a membranous sac of hydrolytic enzymes that animal cells use to digest macromolecules. -Centrosomes (with centrioles): region where the cell's microtubules are initiated; it contains a pair of centrioles. -Flagella (but present in some plant sperm): motility (helps cell move around) structure present in some animal cells, composed of a cluster of microtubules within an extension of the plasma membrane. In plant cells but not animal cells: -Chloroplasts: photosynthetic found in plants and algae and are the sites of photosynthesis. The organelle converts energy to forms that cells can use for work. -Cell Wall: outer layer that maintains cell's shape and protects cell from mechanical damage. Made of cellulose, other polysaccharides, and protein. -Plasmodesmata: channels through cell walls that connect the cytoplasm of adjacent cells. -Central vacuole: prominent organelle in older plant cells; functions include storage, breakdown of waste products, and hydrolysis of macromolecules. Enlargement of vacuole is a major mechanism of plant growth.
Why is membrane selectively permeable
It only lets certain things in and out. The structure of the phospholipid bilayer allows some solutes to cross the membrane freely, some cross with assistance from proteins, and others do not cross at all. This allows for homeostasis