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Final

Biology 1201A Study Guide - Final Guide: Directional Selection, Chromatin, Disruptive Selection


Department
Biology
Course Code
BIOL 1201A
Professor
Michael Gardiner
Study Guide
Final

This preview shows pages 1-3. to view the full 18 pages of the document.
Lecture 1:
- Anthony van Leeuwenkoek made microscopes, first person to see cells and
write down results of what he saw
- Magnification is an enlargement of what you’re looking at without changing it
- Resolution is how close two little dots can be by still looking like two little
dots and not merging together
- Advent microscope allowed people to look at cells much closer to see viruses
- Transmission electron microscope can see inside the cells (cut cells open)
but cells must be dead
- Scanning Electron Microscope looks at surface of things, cells can be alive
- Minimum resolution of light microscope is 0.2 (size of small bacterium) and
light microscopes can magnify up to 1000x the size
- Cell fractionation is taking cells apart to study their components
- Centrifuge: fractionate cells and separate their major organelles (used to
figure out interactions, breaks the cell open and sorts through all the
components in order to see whats happening)
- The cell is the simplest collection of matter which has all the properties of life
- Virus can occur in any organism
- Some virus can be harmful some have no presence
- Can only reproduce when entered into a cell
- Two types of cells: prokaryotic and eukaryotic
- Prokaryotic have no nucleus (genetic info is in area called nucleoid, no
membrane), have a plasma membrane (determines what goes in and out),
ribosomes, nucleoid, cytoplasm, cell wall, pili (rodlike structures around the
cell), flagella (for movement), mesosomes, photosynthetic membranes
- Bacterias range from all sizes and shapes, some are motile and some are not
- Eukaryotic cells have a nucleus and are found in protists, fungi, animals and
plants
- Eukaryotes have plasma membrane, cytoplasm (liquidy part where
everything is stored), nucleus, ribosomes, organelles, endomembrane
system, cytoskeleton (gives shape to the cell), (cell wall, cell matrix, some
organelles, flagella)
- Nucleus is usually the largest organelle, most of the genes stores here (some
in mitochondria and chloroplasts), about 5 microns in diameter, has a double
membrane separating it from cytoplasm but has pores to allow
macromolecules and particles to pass
- Not everything is allowed in and out of nucleus (ex. Proteins are allowed in)
- DNA and associated proteins are organized into chromatin
- As cell prepares to divide, chromatin, chromatin turns into chromosomes
- In the nucleus there is the nucleolus, where rRNA is synthesized and
assembled with proteins with the cytoplasm to form ribosomal subunits
- Some organisms have more than 1 nucleus, animals only have one
- Cytoplasm is the term for everything in the cell between the nucleus and the
plasma membrane, contains all the enzymes the cell will need (approx. 80%
water, nucleic acids, proteins, lipds, carbs, pigments, etc)

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

- Ribosomes contain rRNA and protein and has two subunits that carry out
protein synthesis
- Two endoplasmic reticulums: rough (with ribosomes) and smooth, runs
through the cells
- Cells that synthesize large quantities of proteins have lots of ribosomes
- Free ribosomes are suspended in the cytosol and synthesize proteins that
function within the cytosol
- Bound ribosomes are attached to the endoplasmic reticulum (can switch
between roles)
- Many internal membranes in a eukaryotic cells are part of the
endomembrane system
- Membranes can be in direct contact or connected via transfer of vesicles
(sacs of membrane)
- Endomembrane system includes: nuclear envelope, endoplasmic reticulum,
golgi apparatus, lysosomes, vacuoles, plasma membrane
- Smooth ER is rich in enzymes and plays a role in a variety of metabolic
processes, it synthesizes lipids (including oils, phospholipids and steroids),
also catalyzes a key step in the mobilization of glucose from stored glycogen
in the liver
- Other enzymes in the smooth Er of the liver help detoxify drugs and poisons
- Rough ER is especially abundant in those cells that secrete proteins
- Secretory proteins are packaged into transport vesicles that carry them to
their next stage
- Rough ER is also a membrane factory (membrane bound proteins are
synthesized directly into the membrane, enzymes in the rough ER also
synthesize phospholipids from precursors in the cytosol, as the ER
membrane expands, parts can be transferred as transport vesicles to other
components of the endomembrane system)
Lecture 2:
- golgi apparatus transport vesicles from ER, center of manufacturing,
warehousing, sorting and shipping
- golgi apparatus have cisternae (flat membranous sacs that lok like a sac of
pita bread)
- cis side receives material by fusing with vesicles, while the other side, the
trans side buds off vesicles that travel to other sites (where vesicles leave
the gogli)
- when the vesicle leaves it can go anywhere therefore there are tags on it
telling it where to go
- when the vesicle travels from the cis to the trans, products from the ER are
modified to reach their final state
- can manufacture its own macromolecules, including pectin
- tags, sorts and packages materials into transport vesicles
- lysosomes are membrane-bounded sacs of hydrolytic enzymes that digest
molecules (work best at pH 5)
- massive leakage from lysosomes can destroy a cell (autodigestion)

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

- phagocytosis: when something is infused into the cell (lysosomes can then
fuse with something brought into the cell)
- autophagy is the break down of a material for another use (ex. Tadpole
turning into a frog)
- vacuoles are larger versions of vesicles (food vacuoles fuse with lysosomes,
contractile vacuoles found in freshwater protists, pump excess water out of
the cell and central vacuoles are found in many mature plant cells)
- plant central vacuoles (biggest part of the cell in a plant), have a membrane
surrounding it called the tonoplast, and it transports solutes into the central
vacuole
- functions: stockpiling proteins or inorganic ions, depositing metabolic
byproducts, storing pigments and storing defensive compounds against
herbivores
- cell wall of a plant gives it shape and strength
- tonoplast distinguishes between the central vacuole and other vacuoles
- mitochondria and chloroplasts are the organelles that convert energy to
forms that cells can use for work
- mitochondria generate ATP in cellular respiration (oxygen produces co2 and
atp)
- chloroplasts are the site of photosynthesis (light energy to produce sugar)
- mitochondria has a double membrane system and the inner membrane
increases the surface area, folds in the membrane are called cristae
(equivalent to cytosol in the matrix), very rare to get mitochondria from
father, usually from mother
- inside membranes are thylakoid membranes that have important pigments
for photosynthesis
- membranes are stacked to get as much light as possible (differs in all plants)
- peroxisomes are found in plant and animal cells, they are single membrane
bound compartments, enzymes that transfer hydrogen from various
substrates to oxygen which produces hydrogen peroxide which is converted
to water
- cytoskeleton (network fibers extending through the cytoplasm) organizes
the structures and activities of the cell
Property
Microtubules
Mifrofilaments
Intermediate
Filaments
Structure
Hollow tubules
Two
intertwined
strands
Fibrous
proteins super
coiled
Diameter
25nm
7nm
8-12nm
Protein
Subunits
Tubulin
Actin
Keratin proteins
Function
Maintain cell
shape, cell
motility,
Maintain cell
shape, change
cell shape,
Maintain cell
shape, organelle
anchorage
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