Bio Review unit 1 and 2 Flashcards
nitrogen is an important
element for building …
proteins and nucleic acids.
Phosphorus is important
for building…
nucleic acids and some lipids
Dehydration reaction
bonds two monomers with the loss of H2O
● The -OH of one monomer bonds to the -H of
another monomer forming H2O, which is then
released
- glucose and fructose –> sucrose
○ A+B→AB + H2O
Hydrolysis
breaks the bonds in a polymer by adding H2O
● One -H of the H2O bonds to one monomer and the
remaining -OH of the H2O attaches to the other
monomer
- sucrose-> glucose and fructose
○ AB + H2O → A+B
Carbohydrates contain what groups
carbonyl and hydroxyl
monosaccharides
simple sugars
● Molecular formulas with multiples of the
unit CH2O
● Most common is glucose
○ Nutrients and fuel for cells
■ Used in cellular respiration
● Can serve as building blocks for amino
acids, or as monomers for di- and
polysaccharides
disaccharides
two monosaccharides joined together by
covalent bonds
● Most common is sucrose
○ Monomers of sucrose: glucose and fructose
○ Plants transfer carbohydrates from roots to
leaves in the form of sucrose
Storage polysaccharides
Plants store starch (polymer of glucose monomers)
○ Allows plants to store excess glucose
● Animals store glycogen (polymer of glucose)
○ Stored in liver and muscle cells
Structural polysaccharides
Cellulose: tough substance that forms plant cell walls
● Chitin: forms exoskeleton of arthropods
Function of proteins include
Antibody-help protect the body from disease
○ Enzyme- carry out chemical reactions or assist
in creating new molecules
○ Messenger- transmit signals (ie hormones)
○ Structural- provide structure and support
○ Transport/storage- bind to and carry small
atoms and molecules through the body
levels of protein structure
primary: linear chain of AA
secondary: Coils and folds due to hydrogen bonding within the polypeptide backbone. ᵬ pleated sheet- hydrogen bonds between polypeptide chains lying side by side. A helix as well
tertiary: 3D folding due to interactions between the side chains of the AAs
● Reinforced by hydrophobic interactions and disulfide bridges of the side chains
quaternary: two or more polypeptides
nucleic acid function
Store, transmit and express hereditary information
nucleotides 3 parts
- Nitrogenous base
- Five carbon sugar (pentose)
- Phosphate group(s)
Pyrimidines
one ring with 6 atoms
● Cytosine
● Thymine
● Uracil Only found in DNA
Only found in RNA
Purines
one ring with 6 atoms bonded to one ring with 5 atoms
- adenine and guanine
Saturated fatty acid
no double bonds between
carbons in the carbon chain = more hydrogen
(think: saturated with hydrogen)
Unsaturated fatty acid
contains one or more double bonds
All cells contain
plasma membrane, cytosol, chromosomes, ribosomes
Prokaryote
- domains bacteria and archaea
- Dna is in the nucleotide region
- smaller in size than eukaryotes
Eukaryote
- Protists, fungi, animals, and plants
- DNA is in the nucleus
- Contain bound organelles
Compartmentalization
Membrane-bound organelles allow different parts of the cell to perform different functions at the same time
Plants vs Animals
Plants—cell walls, central vacuole, chloroplasts, plasmodesmata
Animals—centrosomes, lysosomes, flagella
Golgi complex functions
- Receives transport vesicles with materials from the ER
- Modifies the materials (ensures newly formed proteins are folded correctly or modified correctly)
- Sorts the materials
- Adds molecular tags
- Packages materials into new transport vesicles that exit the membrane via exocytosis
Lysosomes functions
- Hydrolyzes macromolecules in animal cells
Autophagy: lysosomes can recycle their own cell’s organic materials - Allows the cell to renew itself
Endosymbiont Theory:
The theory that explains the similarities mitochondria and chloroplast have to a prokaryote
- ● Theory states that an early eukaryote cell engulfed a prokaryote cell
○ Prokaryotic cell became an endosymbiont (cell that lives in another cell)
○ Became one functional organism
cells need a ____ surface area to volume ratio to ____
high, optimize the exchange the material through the plasma membrane
Larger cells have a _____ SA-V
lower, LOSE efficiency exchanging materials
What happens when there is a large cell?
- the cellular demand for resources increase
- rate of heat exchange decreases
Phospolipids are ____
amphipathic
(hydrophilic head n hydrophobic tail and form a bilayer)
integral proteins
Proteins that are embedded into the lipid bilayer
- (transmembrane proteins)
- amphipatic
Peripheral proteins
The proteins of a membrane that are not embedded in the lipid bilayer; loosely bound to the surface of the membrane.
why are membrane carbohydrates important?
cell-to -cell recognition
What is plasmodesmata?
Hole like structures in the cell wall filled with cytosol that connect adjacent cells
What is tocinity?
the ability of an extracellular solution that causes a cell to gain or lose water.
Osmoregulation
cells must be able to regulate their solute concentrations and maintain water balance
in hypertonic water will move to the
to the extracellular fluid
effect: cells shrivel and die
Plasmolysis
vacuole shrinks and the plasma membrane will pull away from the cell wall
In hypotonic what happens to animal and plant cells?
Animal Cells: lyse and swell
Plant cells: cells work optimally (maintain turgor pressure)
What are things that can easily can passed across the membrane?
small nonpolar, hydrophobic molecules such as Hydrocarbons, N2, CO, and O2
What are things that are difficult to pass across the membrane?
Hydrophilic, polar, large molecules, ions such as sugars and water
two categories of transport proteins
channel and carrier
-each transport protein is specific for substances it can facilitate movement for
What are Sodium-Potassium Pumps
Animal cells will regulate their relative concentrations of Na+ and K
- 3 Na+ get pumped out of the cell
- 2 K+ get pumped into the cell
- Results in a +1 net charge to the extracellular fluid
Plants use contrasport for
sugars and amino acids
EX: sucrose-H+ cotransporter
-Sucrose can travel into a plant cell against its concentration gradient ONLY if it is coupled with H+ that is diffusing down its electrochemical gradient
Exocytosis
the secretion of molecules via vesicles that fuse to the plasma membrane
endocytosis
the uptake of molecules from vesicles fused to the plasma membrane
Phagocytosis
when a cell engulfs particles to be later digested by lysosomes
Pinocytosis
nonspecific uptake of extracellular fluid containing dissolved molecules
receptor-mediated endocytosis
specific uptake of molecules via solute binding to receptors on the plasma membrane
what is favorable and unfavorable movement?
- Favorable movement: downhill diffusion
- Unfavorable movement: uphill transport
covalent bonds
when 2 or more atoms share electrons
nonpolar covalent
electrons are shared equally between two atoms
polar covalent
electrons that are not shared equally
ionic bonds
the attraction between oppositely charged atoms
Cohesion
attraction of molecules for other molecules of the same kind
- in plants: H20 molecules stick together
adhesion
the clinging of one molecule to a different molecule
- In plants, this allows water to cling to the
cell walls to resist the downward pull of gravity
- h2o molecules stick to the xylem wall
Density (floating ice)
as water solidifies it expands and becomes less dense
● Due to the hydrogen bonds
● When cooled, H2O molecules move too slowly to break the bonds
○ Allows marine life to survive under floating ice sheets
lipids are nonpolar or polar
nonpolar- hydrophobic
Cholesterol
helps maintain fluidity at high and low temps
■ High temp: reduces movement
■ Low temp: reduces tight packing of phospholipids
glycolipids vs glycoproteins
glycolipids: cholesterol bonded to lipids
glycoproteinsa: cholesterol bonded to proteins
Passive transport
transport of a molecule that does not require energy from the cell because a solute is moving with its concentration gradient
ex: diffusion, facilitated diffusion, osmosis
Channel proteins
provide a channel for molecules and ions to pass
aquaporins: channels for water molecules to pass by
carrier proteins
undergo conformational changes for substances to pass
examples of active transport
- exocytosis, endocytosis, pumps, contrasport
proton pump
integral membrane protein that builds up a proton gradient across the membrane
○ Used by plants, fungi, and bacteria
○ Pumps H+ out of the cell
