Chapter 5: Cells: The Working Units of Life
What 2 features make cells the fundamental units of life?
1. Cell size is limited by surface area-to-volume ratio. 2. Plasma membrane.
What are the 2 types of motor proteins?
1. Dynein 2. Kinesin
What are the 2 components of extracellular structures?
1. Fibrous macromolecule 2. Gel-like medium
What are the 5 functions of the extracellular matrix?
1. Holds cells together in tissues 2. Contributes to physical properties 3. Filter materials 4. Cell movement 5. Chemical signaling
What are the 2 roles of the membrane that surrounds each organelle?
1. Keeps organelle's molecules from other molecules. 2. Acts as a traffic regulator.
What are the 3 functions of the smooth endoplasmic reticulum (SER)?
1. Modification of small molecules 2. Glycogen degradation 3. Synthesis of lipids and steroids
What are the 2 roles of microfilaments?
1. Move cell 2. Cell shape
What are the 4 functions of the plasma membrane?
1. Acts as a selectively permeable barrier. 2. Allows cell to maintain a constant internal environment. 3. Communication. 4. Binding and adhering.
What are the 2 functions of intermediate filaments?
1. Anchor cell in place 2. Resist tension
What are the 5 specific features that characterize prokaryotic cells?
1. Cell walls 2. Internal membrane 3. Flagella 4. Pili 5. Cytoskeleton
What are the 3 components of the cell theory?
1. Cells are the units of life. 2. All living organisms are composed of cells. 3. Cells come from preexisting cells.
What are the 3 types of plastids?
1. Chloroplasts 2. Chromoplasts 3. Leucoplasts
The extracellular matrix is composed of what 3 types of molecules?
1. Collagen 2. Proteoglycans 3. Linking proteins
In what 2 places are ribosomes located in eukaryotic cells?
1. Cytoplasm 2. Endoplasmic reticulum
What are the 3 functions of the nucleus?
1. DNA replication 2. Turn gene transcription on or off 3. Assembly of ribosomes
What is the function of ribosomes?
To synthesize proteins with amino acids.
What is the relationship between surface area and volume?
Volume and surface area do not increase at the same rate. Surface area is slower.
Why is the surface area-to-volume ratio significant biologically?
Volume determines cellular activity. Surface area determines the amount of substances that can enter and exit to participate in cellular activity.
What are the 2 explanations for the how the eukaryotic cell originated?
1. ER as formed by the folding of the plasma membrane 2. Endosymbiosis
What are the 3 components of the cytoskeleton?
1. Microfilaments 2. Intermediate filaments 3. Microtubules
What are 5 organelles present in eukaryotic cells?
1. Nucleus 2. Mitochondrion 3. Endoplasmic reticulum and golgi apparatus 4. Lysosomes and vacuoles 5. Chloroplasts
The endomembrane system includes what 5 organelles?
1. Plasma membrane 2. Nuclear envelope 3. Endoplasmic reticulum 4. Golgi apparatus 5. Lysosomes
What are the 4 general features that characterize prokaryotic cells?
1. Plasma membrane 2. Nucleoid 3. Cytosol 4. Ribosomes
What are the 2 types of lysosomes?
1. Primary 2. Secondary
What are the 4 roles of the golgi apparatus?
1. Receive proteins 2. Packages proteins 3. Adds carbohydrates to proteins 4. Synthesize polysaccharides
What 3 structures have specialized functions, but no membranes in eukaryotic cells?
1. Ribosomes 2. Cytoskeleton 3. Extracellular matrix
What are the 2 types of endoplasmic reticulum?
1. Rough 2. Smooth
What are the 4 functions of the rough endoplasmic reticulum (RER)?
1. Segregation of proteins 2. Modification of proteins 3. Shipping of proteins to other places in the cell 4. Make membrane-bound proteins
What are the 2 roles of microtubules?
1. Skeletal support 2. Framework for movement of structures within the cell
What are the 4 functions of vacuoles?
1. Storage 2. Supports plant 3. Reproduction 4. Digestion
What are the 3 implications of the cell theory?
1. Studying cells is the same as studying organisms. 2. Life is continuous. 3. Life originated from cells.
What are the 3 roles of plant cell walls?
1. Support 2. Barrier 3. Plant form
What are the 5 roles of the cytoskeleton?
1. Supports cell and maintains shape 2. Holds organelles in position 3. Moves organelles 4. Cytoplasmic streaming 5. Anchor cell in place
What is the function of lysosomes?
Break down food.
What is the function of glyoxysomes?
Break down toxic peroxides in plants.
What is the function of peroxisomes?
Break down toxic peroxides.
What is the function of chromoplasts and leucoplasts?
Chromoplasts store pigments, while leucoplasts are storage organelles that do not store pigments.
What is the function of the mitochondria?
Convert chemical energy into ATP.
What is the function of chloroplasts?
Convert light energy into chemical energy.
Where are ribosomes located in prokaryotic cells?
Cytoplasm
What is the function of secondary lysosomes?
Digestion
What is the function of primary lysosomes?
Hydrolyze macromolecules into monomers.
What is a plasma membrane?
Membrane surrounding cell.
What are the 2 organelles that transform energy?
Mitochondria and plastids.
What is the function of cilia and flagella?
Movement
What is the function of the mitochondria's outer membrane?
Offers a little resistance to the movement of substances in and out of the organelle.
What is the function of the mitochondria's inner membrane?
Offers high resistance to the movement of substances in and out of the organelle.
What differentiates eukaryotic cells from prokaryotes?
Organelles
