Cell Structure and Components
What is the cell theory? What are the 3 parts of it?
Cells are the simplest unit of life and are capable of reproduction.
1. All organisms are comprised of cells
2. Cells are the smallest living things
3. Cells arise only from pre-existing cells
How do the sizes of the 3 different types of cytoplasm compare?
Smallest - Microfilaments
Mid-intermediate filaments
Largest - microtubules
What is a hydrogen bond and how does it form?
An attraction between slightly positive hydrogen in one polar molecule and a slightly negative atom in another polar molecule. Intermolecular force.
What are the two main classes of nucleic acids? What component of their structure gives them their name?
Deoxyribonucleic acid and ribonucleic acid. Their unique sugar give their name
What are the 3 main classes of carbohydrates based on polymer size? Refers to as simple sugars.
Monosaccharide: "simple sugars."
Disaccharide
Polysaccharide
Primary differences between prokaryotes and eukaryotes? (where do their names come from)
Prokaryotes are small, simple, and lack a nucleus, and are single-celled. Eukaryotes are larger and more complex, contain a nucleus and organelles, and are either single-celled or multicellular.
What is the microtubule-organizing center (MTOC)? What is its role in eukaryotic cells? For what two events is it most common? What are gamma tubulin rings?
Major assembly site, functions to organize microtubules for motility structures and organize the mitotic spindle in cell division. y-tubulin serves as a nucleation site for building new microtubules.
What are cohesion and adhesion? What properties of water facilitate the formation of each?
Cohesion holds water molecules tightly together. Adhesion is the bond between water molecule and another polar molecule. Hydrogen bonds hold both together.
What is the name of the unique linkage or bond used to link nucleotides in DNA? Which carbon positions on the pentose sugar facilitate this linkage?
Phosphodiester bond. Connects the 3' and 5' positions of separate carbons.
What are isomers? What are structural and stereoisomers? Why are many monosaccharides considered isomers?
molecules that have the same # of atoms. Structural differences are based on how atoms are connected. stereo are differing in spatial orientation.
What is the function of the Eukaryotic Cell Wall? What eukaryotic organisms have cell walls?
Rigid, outer cell boundary that functions to provide structure and stability. Present in plants, fungi, and many protists.
What are capping proteins, and what role do they play in the cell? Why is cell polarization important?
Prevent change in structure or length. centrosome and MTOC cap the minus end. Polarization is important for assembly of tissue, cell communication, and localization of proteins.
What are the properties of hydrocarbons, and where are they typically found in cells?
Most organic moleucles that are carbon chains with hydrogen around. The arrangement influences molecular interactions. Most are found in the plasma membrane, lipids...
How is the double helix of DNA formed? What is unique about the orientation of the two strands, and what type of force/bond is used to hold the strands?
two polynucleotide strands that run anti-parallel and coil around each other. The strands are held together by hydrogen bonds between the nitrogenous bases.
Why can't humans digest cellulose? How do other organisms, such as cows, which lack beta glycosidase breakdown the polymer?
Humans only have alpha-glycosidases and lack the beta-linked ones to break down. Cows have gut bacteria that have the beta-glycosidase present.
What are the following nuclear structures and what do they do: nucleoplasm, nuclear lamina, and nuclear matrix?
Nucleoplasm --> inner contents of nucleus (nucleus cytoplasm)
Nuclear Lamina --> dense, fibrous protein network which provides structure to the nucleus and facilitates disassembly in CD.
Nuclear Matrix --> network of fibers serving as a scaffold to establish designated chromosome territory.
What are intermediate filaments? Where are keratins, vimentins, neurofilaments, and lamins found and associated?
Toughest and most durable, which function in cell mechanical support, resist stretching, and form scaffolding.
Keratins - epithelial cells, cytoplasmic and most diverse.
Vimentin - connective tissue, muscle
Neuro - neurons
Lamins - nuclei of all animal cells
What are the 2 reactions that govern the assembly and disassembly of polymers, and how do they work?
Formed through dehydration rxn which removes a water molecule.
Broken down through hydrolysis, which adds a water molecule to break a bond in the polymer backbone.
What are the 3 primary types of RNA found in cells, and what do each do?
mRNA - contains genetic info for amino acid sequence. template for translation.
rRNA - made in the nucleus and is part of the ribosomal structure.
tRNA - transfers amino acids to the ribosome in translation.
Where is energy stored in triglycerides? How are triglycerols named? What causes kinks in fatty acid chains?
The C-H bonds of the fatty acid chains. Named based on length and presence of double bonds. Kinks caused by double and triple bonds.
What are the properties of cells? In other words, what constitutes life? What is meant by the terms metabolism and homeostasis?
1. Cellular organization
2. Reproduction
3. Heredity
4. Growth and development
5. Metabolism - ability to obtain and use energy for
6. Response to stimuli
7. Homeostasis - regulation and maintenance
8. Evolutionary adaptation
How do tubulin dimers assemble into microtubules? What is meant by the plus end and the minus end of a tube? What two monomers comprise a tubulin dimer? What end grows fastest?
Each has polarity and orientation. Plus end has exposed beta monomers, and the minus end has alpha monomers. Plus end moves fastest using GTP for polymerization.
Why is liquid water more dense than solid water? Why is this important in Bio?
When liquid turns to a solid it forms a crystalline structure with hydrogen bonds that force the molecules to spread out further. This is important in ice and its properties in the enviroment
What types of jobs or roles do proteins play in cells?
2. Immune defense
3. Transport
4. Structural support
5. Motion
6. regulatory
7. storage
8. receptor
What are the 3 main lipids that are found in the plasma membrane, and what are their functions? Which is most common and why?
Phospholipids (75%) form the phospholipid bilayer.
Cholesterol - provide stability and fluidity with temp changes.
Glycolipids - like phospholipids, but with a carbohydrate group instead of a polar head group