Genbio w1-2 Flashcards
the basic unit of life that do metabolic processes necesssary to live
Cell
interaction of different ecosystems
Biosphere
interaction between 2 or more organisms
Ecosystem
In 1665, _______ built a microscope and examined thin slices of cork cut with a penknife and called the little compartments cells, from the Latin “cellula” meaning “little room”
Robert Hooke
-Produced small lenses that could magnify objects to 300X their size.
-_________ became the first to observe living cells, including blood cells, sperm cells, bacteria and single celled organisms found in the pond water.
Antonie van Leeuwenhoek
What name did Antonie van Leeuwenhoek give for cells
animalcules
what does the word cellula mean
“little room”
-A hypothetical process by which living organisms develop from nonliving matter.
-Historical documents contain “recipes” for creating creatures such as : bees, frogs and mice.
-The “recipes” were based on observations.
*When the Nile river flooded, soon many frogs appeared in the mud.
*If damp rags were left in a pile of wheat grain, many mice appeared 21 days later.
Spontaneous Generation
-first to disagree with spontaneous generation (and proved it wrong)
Results from his experiment:
-when broth was heated and left the flask open: microbial growth
-when broth was heated and sealed: no bacterial growth
-when opened again: microbial growth
Lazzaro Spallanzani’s
-spontaneous generation believers did not believe Lazarro, stating that his setup was wrong because he removed oxygen, so another person challenged this belief
-used meat and gauze-covered container
Results from his experiment:
Open container: formation of maggots
Cork-sealed container: no maggots
Gauze-covered container: no maggots
no one believed him though
Francesco Redi’s Experiment
-Similar setup to Lazarro’s except microbial growth occurred in the heated sealed flask
-means that certain conditions are needed for abiogenesis to happen
John Needham
what was wrong with John Needham’s experiment
because the heat is not high enough to kill all the microorganisms
-officially disproved spontaneous generation
-used uniquely shaped flash, which was left open, but its curve prevents outside air from entering the flask
Louis Pasteur
found out in 1831 that every plant cell he looked at contained a rounded structure, which he called nucleus (Latin word for “kernel”)
Robert Brown
In 1838, came to importantly conclude that all plant tissues are composed of cells and that embryonic plant always arises from a single cell.
Matthias Schleiden
(1839) reported similar conclusions regarding animal tissues.
Theodor Schwann
Three principles of cell theory
- All organisms consist of one or more cells.
- The cell is the basic unit of structure for all organisms.
- All cells arise only from pre-existing cells
(1855) concluded that cells arose only by the division of preexisting cells. (Latin phrase “omnis cellula e cellula”)
Rudolf Virchow
4 statements of Modern Cell theory
- The cell contains hereditary information (DNA) which is passed on from cell to cell during cell division.
- All cells are basically the same in chemical composition and metabolic activities.
- All basic chemical & physiological functions are carried out inside the cells
- Cell activity depends on the activities of sub-cellular structures within the cell
2 Types of cells
Prokaryotic and Eukaryotic cells
Basic features of all cells
-plasma membrane
-semifluid substance called cytosol
-chromosomes (carry genes)
-ribosomes (make proteins)
Characteristics of prokaryotic cells
i.e. archae, bacteria
-simple, single-celled (unicellular) organism that lacks a nucleus
-DNA in an unbound region called nucleoid
-no membrane-bound organelles
-cytoplasm bound by the plasma membrane
-has a cell wall
Characteristics of eukaryotic cells
i.e. amoeba, animals, plants, fungi
-DNA in a nucleus that is membrane bound
-includes numerous membrane bound organelles
-cytoplasm in the region between the plasma membrane and nucleus
-generally much larger than prokaryotic cells
Surface area to volume ratio of a cell is critical
The logistics of carrying out a cellular metabolism sets limits on the size of cells
(basa lang HAHAH)
As the surface area increases by a factor of n^2, the volume increases by a factor of n&3
Small cells have a greater surface area relative to volume
Categorization of prokaryotic cells (according to reaction when doing gram staining procedure)
Gram negative bacteria- pink color
Gram positive bacteria- purple/violet stain
Categorization of prokaryotic cells (according to shape)
- cocci- circular
- bacilli- elongated
- coccobacillus- mix of 1 and 2
- staphyloccocus- grouped together/clustered
key words: -us prefix if singular, diplo if double, strepto if chained
Other shapes of prokaryotic cells
others:
palisades- vertical rows of bacilli
sprilla- spirally shaped bacteria
corneybactirium- club shaped
vibrios- comma shaped
spirochete- like spirilla but more flexible
How would you identify if a subcellular structure is an organelle
If it is membrane bound
Categorization of Eukaryotic cells
- Animal cell
- Plant cell
-cell membrane, cytoplasmic membrane, plasmalemma
-contains cell contents
-maintains shape of cell
-cell recognition and communication
-made up of phospholipid bilayer and proteins
Plasma Membrane
-mostly present in prokaryotes and some in eukaryotes (certain species of fungi)
-self replicating and stable extrachromosomal units of circular DNA (not part of the main chromosomal structure/main DNA)
-not critical to basic functions of the cell (but can encode certain characteristics that is contributory to the overall survival of the cell in certain situations, i.e. antibiotic resistance)
-can be transferred from one prokaryotic cell to another via pili
Plasmid
-states that membranes are composed of phospholipid bilayer with various protein molecules roaming around within it
Fluid Mosaic model
What is the structure of phospholipid bilayer
It has a polar/hydrophilic head and non polar/hydrophobic tail (amphipatic)
-jelly like structure
-contains all organelles except nucleus
Cytoplasm
semifluid substance minus the organelle
Cytosol
-contains DNA (for eukaryotic cells)
-2 membranes: inner and outer membrane
-pores are present
Nucleus
-responsible for synthesizing and assembling RNA and protein needed to form ribiosomes
Nucleolus
-responsible for protein synthesis
-found in all cells but differ from size and number (smaller for prokaryotic cells)
Ribosomes
Sedimentation coefficient rate at which proteins carry out protein synthesis
Svedberg units (s)
Svedberg units of Eukaryotes
80s (60 s & 40s) with 78 proteins
Svedberg units of Prokaryotes (bacteria and archae)
70s (50s & 30s)
55 proteins for bacteria and 65 for archae
-where ATP is created
-site of aerobic respiration
-in humans, it is only inherited from the mother
-location and number depends on their roles
-double membrane
Mitochondria
accounts for more than half of the total membrane in many eukaryotic cells
Endoplasmic reticulum
-found only in plant cells
-site of photosynthesis in plants and algae
-5 to 10 micrometers (μm) long
-also contains enzymes
-plastids:plant organelles
chloroplast (green)
rhodoplast (red) and phaeoplast (brown)
Leucoplasts
amyloplast (starch), elaioplast (oil), proteinplast (protein
-detoxifies posion
-synthesizing lipids
-metabolizing carbohydrates
-stores calcium
Smooth ER
-distributes transport vesicles, proteins surrounded by membrane
-membrane factory of cell
Rough ER
-Discovered by Camillo Golgi
-processing, packaging secretory proteins and synthesizing complex polysaccharides
Golgi complex
-packages the protein from Golgi apparatus
-abundant in pancreas
Secretory vesicles
-stores hydrolases
-suicide bags
-contains unecessary molecules to breakdown peroxisome
-lacks structure
-generate and degrades hydrogen peroxide (H2O2)
-abundant in liver and kidney in animal cells
Lysosome
-structure made of microtubules
-orientation and attachment of microtubules to chromosome during cell divisions
-found as a single structure in cilia and flagcella in animal cells and lower plant cells
-absent in most higher cells
centriole-microtubules
centrisole- centrioles and microtubules
Centrioles
