Topics 1.1 - 2.2 Review of notes presentation Flashcards
Decreasing order of element abundance in living organisms
CHON
Carbon, Hydrogen, Oxygen, Nitrogen
SPONCHNa CaFe
Sulfur, Phosphorus, Oxygen, Nitrogen, Carbon, Hydrogen, Sodium, Calcium, and Iron
Sulfur in living organisms
amino acids (proteins - disulfide bridges)
phosphorus in living organisms
Phospholipids, Nucleic acids (DNA and RNA), ATP
Oxygen in living organisms
Amino acids (proteins), carbohydrates, lipids, nucleic acids (dna and rna) aerobic respiration
Nitrogen in living organisms
amino acids (proteins - amine groups), Nucleic acids (Dna and Rna nitrogenous bases) ATP
Carbon in living organisms
forms the foundation for all organic molecules/compounds, carbohydrates, lipids, proteins, nucleic acids
Hydrogen in living organisms
amino acids (proteins) carbohydrates, lipids, nucleic acids, respiration, photosynthesis
Sodium in living organisms
osmoregulation, action potentials (nerve signals - sodium channels open, sodium ions rush into nerve cell causing depolarization)
Calcium in living organisms
muscle contraction, nerve cell transmission (Ca ions rush into nerve cell causing vesicles with neurotransmitter to bind with presynaptic membrane and “dump” neurotransmitter into synaptic cleft)
Iron in living organisms
in cytochromes (proteins that make up the electron transport chain - respiration and photosynthesis) in hemoglobin (oxygen transport in blood)
Thermal properties of water (due to hydrogen bonds)
High specific heat: stabilizes environments for life; a large amount of heat only raises water temp a small amount
Thermal properties of water (due to hydrogen bonds)
- High specific heat: stabilizes environments for life; a large amount of heat only raises water temp a small amount
* heat energy is used to break hydrogen bonds before individual water molecules heat up - high heat of vaporization: evaporative cooling for organisms (ie) sweat
Cohesive and adhesive properties of water due to hydrogen bonds
- high surface tension: organisms live on surface and maintains lung structure in pleural membranes
- transport in plants: hydrogen bonds “stick” water molecules together (cohesion) and to other substances (adhesion - ie xylem walls)
* allows movement of water through plants (transpiration)
Solvent properties of water (due to polarity) universal solvent
- Dissolves and transports polar/hydrophilic substances - nutrients around organisms
- sap in plants
- blood in animals (glucose) - medium for metabolic reactions (DNA replication, transcription, and translation)
Water is used in living systems to…
make and break chemical bonds
How does water create bonds
water is removed from two subunits (H+ from on and OH- from another) of a macromolecule
how does water break bonds
water is added to macromolecules (H+ and OH)
Condensation
Creating larger molecules by removing water (water is produced)
Hydrolysis
(hydro = water, lysis = “slice/dice”)
Water is added to break bonds/break larger molecules into smaller pieces (ie digestion)
Cell theory (3)
All living things are made of cells
cells = smallest fundamental unit of life
all cells arise from pre-existing cells
Evidence for cell theory (3)
- microscopes allow visualization of cells
- nothing smaller than a cell found to survive (on own)
- sterilization prevents cell growth (cells can only come from other cells)
Exceptions to the cell theory
- multinucleate muscle cells and fungal hyphae
- giant algae
- viruses
- first cell origins (spontaneous)
All cells carry out…
the basic functions of life (reproduction/growth, respiration for energy and nutrients, homeostasis)
Size units of molecules, cell components, and cells
Molecules: 1nm Cell membrane: 10nm Viruses: 100 nm Bacteria: 1 um Organelles: up to 10 um Eukaryotic cells: 100 um
why are cells so small
because they need to maintain a large surface area and small volume (SA/V ratio)
Cells want to…
maximize SA/V ratio (bigger) so there is more surface area and less volume
surface area
determines the rate of exchange of materials (nutrients and waster)
volume
influences metabolic reaction rate/determines need of nutrients and amount of waste
as cell size increases:
SA/V ratio decreases
as cell size increases:
SA/V ratio decreases
- cells divide when they are too large to maintain a high SA/V ratio
Multicellular organisms show…
emergent properties
interactions btw cell components produce new properties/new functions that individual cells wouldn’t be able to do on their own (ie; cells to tissues, tissues to organs)
cells in multicellular organisms differentiate to…
carry out specialized functions by expressing some of their genes but not others
- all cells have a complete set of DNA
- different genes turn on - makes them more specialized for a function
2 things stem cells can do
- divide
- differentiate along different pathways
- stem cells = undifferentiated (can continuously divide and become any cell)
outline therapeutic uses of stem cells
- stem cells are harvested from embryos, placenta, or umbilical cord (destroys embryo)
- exposed to biochemicals in lab to cause differentiation to specific cell type
- transferred to patients
- photoreceptor for Stargardt’s disease
- blood cells for leukemia
what do stem cell transfers require
immunosuppression of the patient so they don’t reject the cells
monitor for cancer following the transfer
prokaryotic cells
- divide by binary fission (asexual reproduction)
- have organelles without membranes around them
endosymbiotic theory
- mitochondria and chloroplasts are thought to have originated from primitive prokaryotic cell that was engulfed by a heterotrophic cell
cytoplasm function in eukaryotic cell
fluid containing enzymes for metabolic reactions
flagellum function in eukaryotic cell
mobility
ribosomes (70s) function in eukaryotic cell
protein synthesis
nucleoid function in eukaryotic cell
region where DNA is located (cellular control and reproduction)
plasma membrane function in eukaryotic cell
entry/exit of substances
cell wall function in eukaryotic cell
shape/protection/water uptake
capsule function in eukaryotic cell
protection (from dehydration)
plasmid function in eukaryotic cell
additional DNA (can replicate independently)
pili function in eukaryotic cell
attachment (some aid in exchange of genetic material)
Eukaryotic cells
- have membrane bound organelles (discrete structures that carry out specialized functions)
ribosomes (80s) function in eukaryotic cells
protein synthesis (bound to ER = make proteins for excretion or free floating = make proteins that are used in the cell)
endoplasmic reticulum (ER) function in eukaryotic cells
rough - protein synthesis (excretion)
smooth - hormone production, detoxification, lipid production
nucleus function in eukaryotic cells
contains DNA (cell control and reproduction)
nucleolus function in eukaryotic cells
makes ribosomes
lysosome function in eukaryotic cells (animal cells - only one membrane)
plastid = plant cells
“slice and dice” - hydrolytic enzymes for intracellular digestion
golgi apparatus function in eukaryotic cells
collects, stores, modifies, and transports cellular materials from ER
Mitochondria function in eukaryotic cells
powerhouse of the cell
produce ATP
Centrosome/centrioles function in eukaryotic cells
organize microtubules for cell division and mobility
chloroplast function in eukaryotic cells (plants)
photosynthesis
vacuoles function in eukaryotic cells
storage of nutrients (starch, water, glycogen) in very large plants
similarities btw prokaryotic cells and eukaryotes
- have DNA
- have a cell membrane
- carry out functions of life
- have cytoplasm
- have ribosomes
what makes prokaryotic and eukaryotic cells different
pro: DNA is naked
Euk: DNA associated with proteins
pro: DNA is circular
Euk: DNA linear
pro: DNA does not contain introns
Euk: DNA has many introns
Pro: no membrane bound organelles or mitochondria
euk: membrane bound organelles and mitochondria
pro: 70s ribosomes
euk: 80s ribosomes
pro: smaller than 10um
euk: larger than 10 um
differences between plant and animal cells
a: no cell walls
p: cell walls
a: centrioles
p: no centrioles
a: no chloroplasts
p: chloroplasts
a: small (if any) vacuoles
p: large central vacuoles
a: carbohydrates stored as glycogen
p: carbohydrates stored as starch
a: cholesterol in cell membrane
p: no cholesterol in cell membrane
Bacteria and outmost part w unique characteristic
cell wall - peptidoglycan
fungi and outmost part w unique characteristic
cell wall - chitin
yeast and outmost part w unique characteristic
cell wall - glucan and mannan
algae and outmost part w unique characteristic
cell wall - cellulose
plant and outmost part w unique characteristic
cell wall - cellulose
animal and outmost part w unique characteristic
no cell wall - surrounded by glycoproteins
cell wall function
maintain cell shape and regulate water uptake
in plants: water in cells presses out against cell wall, creating turgor pressure for vertical support
ECM
anchored to cell membranes by collagen and glycoproteins
allows attachment between cells, cell to cell interaction, communication, coordination in tissues, movement
Explain how the hydrophobic and hydrophilic properties of phospholipids help to maintain the structure of cell membranes
- Phospholipids have hydrophilic (water-loving) heads (polar) and hydrophobic (water-fearing) (nonpolar) tails (amphipathic molecules
- Phospholipid bilayer (two layers) forms with polar heads toward water on both sides of the membrane (cytoplasm and extracellular fluids) and tails away from water (in the center of the bilayer)
- Hydrophobic interactions between tails and hydrophilic interactions between heads and water stabilizes membrane structure
- interactions of phospholipids allow membrane fluidity (breaking of membrane in endo and exocytosis)
Functions of membrane proteins
TRACIE
T: transport (active and facilitated)
R: receptors (hormones ie insulin)
A; anchorage (for cytoskeleton and to ECM)
C: Cell recognition (antigens)
I: intercellular connections (plasmodesmata)
E: enzymatic activity (metabolic reactions)
passive membrane transport
movement of substances across the cell membrane/lipid bilayer
movement of particles from high (hypertonic) to low (hypotonic) concentration
moves down the concentration gradient toward the equilibrium to create an isotonic solution
kidney dialysis is based on concentration gradients
examples of passive transport: diffusion
Diffusion: small, nonpolar molecules move through membrane from higher (hypertonic) to lower (hypotonic) concentration
nonspecific protein channels allow small, polar ions to diffuse
Example of this is gasses in alveoli in lungs
examples of passive transport: osmosis
osmosis: diffusion of water molecules to balance solute concentrations (moves from low solute to high solute concentrations)
* important in transplants so tissues/organs bathed in isotonic solutions
examples of passive transport: facilitated diffusion
diffusion of large molecules through specific protein channels (pores) in the membrane (proteins change shape to “facilitate this movement)
what is membrane transport
movement of substances across the cell membrane/lipid bilayer
active membrane transport
movement of particles from low to high concentrations against a concentration gradient
it requires protein pumps and ATP
example of active transport
sodium/potassium pump: maintains resting potential in nerve cells
pumps 3 sodium out and 2 potassium in against their concentration gradients
Endocytosis (ATP)
- vesicles move large substances into cell (invagination of membrane - pinches off to form vesicle around large solide substances (phagocytosis) or large amounts of liquid pinocytosis)
exocytosis (ATP) secretion
- vesicles (from RER then to golgi apparatus) move toward and fuse with cell membrane, dumping contents into extracellular space
(secretion - molecules/substances exit the cell)
Cell Cycle
somatic body cells (2n = 2 copies of each chromosome from 2 parents) go through mitosis to produce 2 genetically identical daughter cells
Cell cycle order
Interphase
mitosis
cytokinesis
interphase order
G1
Synthesis
G2
Mitosis (and cytokinesis) order
prophase metaphase anaphase telaphase cytokinesis
Interphase
G1: growth, protein production, metabolic reactions
S: synthesis - DNA replication - copied chromosomes attached at centromere - (copies = sister chromatids)
G2: growth, protein production, duplication organelles)
prophase
nuclear membrane disappears, chromosomes condense and become visible, mitotic spindle forms
metaphase
chromosomes (as sister chromatids) line up individually (NOT AS HOMOLOGOUS PAIRS) along the middle of the cell
anaphase
centrioles split, sister chromatids seperate, one copy of each chromosome is pulled to opposite ends of cell by mitotic spindle fibers
Telophase
nuclear membranes begin to reform and cytoplasm divides
cytokinesis
two identical diploid (2n - 2 copies of each chromosomes) daughter cells are formed
cytokinesis: animals vs plants
animals (have boobs): happens by means of cleavage furrow
plants: cell plate (new cell wall formed by vesicles causes cytokinesis
what stage do cells spend most of their lives in and why
interphase because they are working for the body
what are the reasons that cells divide
TOAD
T: tissue repair/replacement
O: Organism growth
A: asexual reproduction (ie - binary fission, stem cuttings in plants)
D: Development (from fertilized egg - embryonic development)
IF THE SA/V RATIO IS TOO SMALL
what are cell “checkpoints”
cell cycle process stops and cell health is checked before being allowed to continue dividing
what is cell division controlled by?
- cyclins
- four different cyclins
- cyclins activate cyclin-dependent kinases
- different cyclin and CDK’s at different times for different reactions so processes happen in the correct order
- tumor suppressor genes inhibit cell growth
- oncogenes promote cell growth
- mutations to either genes can cause cancer
- mutations caused by mutagens like radiation and cigarette smoke
what is the big difference between methane and water
water is polar and can form hydrogen bonds
why is davson-danielli’s model falsified and singer-nicolson’s model accepted
- hydrophobig portions could not form a continuous layer with water so they must be embedded within the protein
- membranes are fluid and not in a fixed position
- globular proteins are integral and peripheral
how were cyclins discovered
on accident
First cell origins
must have arrived from non-living matter so the following theory must have occurred
1) there was non-living synthesis of simple organic compounds
2) these simple organic compounds became more complex polymers
3) some polymers became self-replicating
4) these molecules became packaged in membranes
- discovered by recreating the conditions of early earth using closed flasks; able to generate simple organic compounds from non-living matter
falsification of theory of vitalism
theory states that organic compounds can ONLY be made by living systems which posses a “vital force”
Woehler heated ammonium sulfate and created urea (an organic compound)
artificial synthesis of urea falsified vitalism
