MIDTERM Flashcards
What is a reductionist approach? How did it help with the discovery of cells?
Reductionist: The premise that studying the parts of the whole can explain the character of the whole. (Small -> big)
Cell biology follows this idea.
What is Microscopy?
An instrument that provides a magnified image of the tiny object. Allowed cell visualization beyond human vision.
What is cell theory?
3 major points:
1. All organisms are composed of one or more cells
2. The cell is the structural unit of life
3. Cells arise from pre existing cells
One newer point: Cells contain genetic information that is passed on to the next generation
What is the structural unit of life?
A CELL!
What is it called when a cell is isolated outside of its environment?
“In Vitro”
Cultured cells are essential for cell biologists.
What do cells from different species share in common?
Similar structure, composition, and metabolic features.
What are genes?
Where Information for building an organism is stored. Genes store info for:
- Constructing cellular structures
- Running cellular activities
- Replication capability.
How do cells replicate?
Division, contents of a mother cell are distributed into two daughter cells. Cells can be either haploid (n) or diploid (2n).
What to cells use in order to function?
Energy. Can be in multiple forms (light -> chemical = photosynthesis… OR glucose -> ATP)
What does the sum total of chemical reactions in a cell represent?
The cells metabolism. Cells function as mini chemical plants.
How do cells engage in mechanical activities?
Cells can: transport materials, assemble and disassemble, and move from one site to another.
Activities are based on: dynamic, mechanical changes within cells.
How do cells respond to stimuli?
Most cells are covered with receptors that interact with substances in the environment.
- Cells can also respond by altering metabolism, moving from one place to another, or even self destruction
How do cells self regulate?
Cells are robust and have feedback loops to maintain homeostasis.
How did cells evolve?
All organisms evolved from a common ancestral cell that lived more then three billion years ago. Despite this evolution is ongoing and essential for survival.
What are the features of a eukaryote?
Eukaryotic: plants, animals, fungi, protists
- Have nucleus, specialized organelles, Divide by mitosis, can be uni or multicellular, DNA is in chromosomes.
- Use cytoplasmic movement and cilia and flagella,
What are the features of a prokaryotic cell?
Prokaryotic - Bacteria
- No nucleus, Small, no membrane bound organelles, unicellular, DNA = long strand
- Divide by fission, Have flagella, do not have spindle
What are the similarities between Eukaryotic and prokaryotic cells?
They both have: Have ribosomes, DNA, Cytoplasm, Cell membrane, flagella
What are the limiting factors in cell size?
Surface area to volume ratio..
What is a virus?
Virus: Pathogen and intracellular obligate parasites.
What is a Virion?
Virion: Virus particle outside of the host cell. Contains genetic material plus protein subunits.
What is a bacteriophage?
Bacteriophage: Viruses that infect bacteria
What is a viroid?
Viroid: Pathogen consisting of a small naked RNA molecule which can cause disease by interfering with gene expression in host cells.
What is a Lytic infection?
Lytic infection: the virus redirects the host into making more virus particles, host cell lyses and releases the virus
What is integration? (in the context of viruses and viroids)
Integration: The virus integrates its DNA (provirus) into the host cells chromosomes.
What are the basic properties of cells?
- Cells are highly complex and organized
- Cells poses genetic program and a means to use it
- Cells are capable of reproduction
- Cells acquire and use energy
- Cells carry out a variety of chemical reactions
- Cells engage in mechanical activities
- Cells can respond to stimuli
- Cells can self regulate
- Cells evolve
What is the difference between polar and non polar molecules?
Polar: Assymetric distribution of charge due to a difference in EN
Non polar: Lacks EN atoms and polar bonds
What is an ionic bond?
Attraction between oppositely charged groups in a molecule.
What is a Hydrogen bond?
When hydrogen bears a partial positive charge when covalently bonded to an electronegative atom.
What is a hydrophobic interaction?
When molecules act differently in the presence of water.
- Polar molecules: Hydrophilic
- Nonpolar molecules: Hydrophobic
What is a Vanderwaals force?
When two molecules that have transitionary dipoles are close to another and experience a weak attractive force.
What are Acids, bases, and buffers?
Acid: releases protons
Base: accepts protons
Buffers: resist PH changes.
What are functional groups?
Units within a molecule that give molecules their physical properties, reactivity, and solubility.
What are Carbohydrates?
Carbohydrates: Include simple suars and polysaccharides. Function primarily ad stores of chemical energy.
What are nutritional polysaccharides? (Examples)
Polysaccharide: polymers of sugar joined by glycosidic bonds.
- Glycogen: animal product made of glucose polymers
- Starch: plant made of branched and I branched glucose polymers
What are examples of structural polysaccharides?
Cellulose, Chitin, sand GAGs/
What are fats?
Fats: Glycerol linked by ester bonds to three fatty acids (Triacylglycerol)
- Use hydrophobic interactions to their advantage
- differ in length and saturation.
- Saturated = lacks double bonds, unsaturated = has double bonds
What are steroids?
Steroids: built around a four ringed hydrocarbon skeleton. (Ex. Estrogen)
What is a phospholipid?
Phospholipid: Resembles a fat but only has two fatty acids, the third hydroxyl group of glycerol is bonded to a phosphate group.
- Membrane
What are Amino acids?
Amino acids: building blocks of proteins, all have carboxyl and amino group separated by alpha carbon.