Smartbook 3 Flashcards
Cell biology
The study of individual cells and their interactions with each other
Cell theory
- All living organisms are composed of one or more cells
- Cells are the smallest units of life
- New cells come only from pre-existing cells by cell division
The function of DNA in cells
Stores genetic information
The function of RNA in cells
Acts as intermediary in the process of protein synthesis and plays other important roles such as ribozymes
The function of proteins in cells
Form the foundation of the structure and activities of cells
Primodial soup
The product of spontaneous appearance of organic molecules (esp. Nucleotides + Amino Acids), eventually give rise to living cells
Early earth environment was ideal for accumulating organic matters because…
- Little free oxygen for oxidation
- No living organisms to metabolize organic matter
Prebiotic soup
The slow accumulation of organic molecules in early oceans; key event in preceding the origin of life
Reducing atmosphere hypothesis
Oxidation-reduction (redox) reactions may be responsible for the formation of complex organic molecules from simple organic molecules
*Involves: Water vapor, hydrogen gas, methane, and ammonia
Extraterrestrial hypothesis
Organic molecules traveled to Earth from asteroids and comets in the form of meteorites
Carbonaceous chondrites
Meteorites that may contain a substantial amount of organic carbon, including amino acids and nucleic acid bases
Deep-sea vent hypothesis
Extreme temperatures, metal ions, H2S and NH3 interact, leading to organic molecules
Biological communities found in the deep-sea vent
Fish, worms, clams, crabs, shrimp, and bacteria — all receive energy from chemicals in the vent and not from the sun
Stage 2 of the origin of cells involve ____ ____ (macromolecules) forming on the surface of ____
Organic polymers; clay
4 Key features of the characteristics that makes protobionts possible precursors of living cells
- A boundary that separates the internal contents of the protobiont from the external environment
- Polymers inside the protobiont contained information
- Polymers inside the protobiont had catalytic functions
- The capability of protobionts to self-replicate
3 key functions of RNA in the RNA world
- Store information in nucleotide base sequence
- The nucleotide sequence has the capability of self-replication
- Ribozymes: RNA molecules that can catalyze chemical reactions
Chemical selection
When a chemical within a mixture has special properties/advantages that cause it to increase in amount relative to other chemicals in the mixture
Why was the RNA world suspended by the modern DNA/RNA/Protein world?
- The function of information storage was taken by DNA
- Metabolism and other cellular functions are taken care of by proteins that has a greater catalytic ability than RNA molecules
Microscopy
Using microscopes to take micrographs
Resolution
A measure of the clarity of an image; the ability to observe 2 adjacent objects as distinct from one another
Contrast
Relative difference in lightness, darkness, or color between adjacent regions in a sample
Magnification
The ratio between the size of an image produced by a microscope and the objects actual size
Light microscope
Uses light for illumination
- Can resolve structures as close as 0.2 micron (micrometer) from each other
Electron microscope
Uses a beam of electrons for illumination
Transmission electron microscopy (TEM)
A beam of electrons are transmitted through a biological sample
Scanning electron microscopy (SEM)
Used to view the surface of a sample; sample coated with heavy metal, then exposed to an electron beam that scans its surface
Protein-protein interactions
Proteins binding together and creating intricate cell structures and also facilitate processes in which proteins interact in a consistent series of steps
Genome
The entire complement of its genetic material
Genes
(Within each species’ genome) contains the information to produce proteins largely responsible for determining cell structure and function
Categories of prokaryotic cells
Bacteria and Archaea
Glycocalyx
An outer viscous covering surrounding a bacteria; traps water and helps protect it from drying out
Capsule
Keeps the bacteria from being destroyed by an animal’s immune system; aid in the attachment to cell surfaces
Archaea are like bacteria, they are very widespread across the world, except they are ____ common and often occupy ____ environments
Less; extreme
Shared structures of prokaryotic cells
- Pili
- Plasma membrane
- Cytoplasm
- Nucleoid
- Ribosomes
- Cell wall
- Flagella
Pili
Allow cells to attach to surfaces
Plasma membrane
Double layer of phospholipids and embedded proteins that forms the barrier between the interior of the cell and its environment
Cytoplasm
Region of the cell contained within the plasma membrane
Nucleoid
Where the genetic material is located; found in prokaryotics only — not membrane bound
Ribosomes
Involved in polypeptide synthesis
Cell wall
Supports and protects the plasma membrane and cytoplasm; nearly all species have a relatively rigid one
Flagella
Provide prokaryotic cells with the ability to move
Eukaryotic cells are ____ by internal membranes to create ____
Compartmentalized; organelles
Eukaryotes are all species other than ____ and ____
Bacteria; archaea
Organelle
A membrane-bound compartment with its own inquest structure and function
Cytosol
Region of an eukaryotic cell outside of organelles but inside the plasma membrane; also a central coordinating region for many metabolic activities of eukaryotic cells
The cytoskeleton is made up by ____ types of protein: ____, ____ and ____
Microtubules; intermediate filaments; actin filaments
Microtubules
Hollow protein filament, important for cell shape, organization, and movement
Intermediate filaments
Animal cells only; helps maintain cell shape and rigidity
Actin filaments
Thin type of protein filament composed of actin proteins, supports the plasma membrane and play a key role in cell strength, shape, and movement
Motor proteins
A category of proteins that uses ATP as a source of energy to promote movements
Cilia and flagella are two types of cell appendages that uses ____ and ____ to facilitate movement
Microtubules; motor proteins
Endoplasmic Reticulum (ER)
A network of membranes that form cisternae and fluid-filled tubules; both are continuous structures
Lumen
The internal space of an organelle (or an organ)
Rough ER has its outer surface studded with ____, giving it a ____ appearance
Ribosomes; bumpy
Functions of the rough ER
- Sort proteins that are destined for the ER
- Insert newly made proteins into the ER membrane
- Glycosylation: Attach carbohydrates to proteins and lipids
Smooth ER lacks ____ compared to the rough ER
Ribosomes
Functions of the peroxisome enzymes
Detoxification, and the metabolism of both amino acids and fats
Functions of the Golgi Apparatus
Sorting, secretion, and processing of proteins
Semiautonomous organelles in eukaryotic cells are…
Chloroplasts & mitochondria
Chaperones
Proteins that guide other proteins along the proper pathways of folding
Cotranslational sorting
Proteins destined for the ER, Golgi, lysosome, plasma membrane or secretion are first directed to the ER
