ap bio unit two

2.3b main concepts

* as cell volume increases or a cell becomes specialized for transport across its surface there are structural modifications such as membrane folds that are necessary to adequately exchange molecules from or into the environment * as organisms increase in size, their surface area - volume ratio decreases which makes it harder to release heat energy and adaptations make improve an organism's efficiency in doing so (ex: elephant's overall small ratio compared to large surface area of their ears) * cells and organisms use specialized exchange surfaces (ex: stomatal openings on the surface of leaves)

2.11 main concepts

* both prokaryotic and eukaryotic cells have external plasma membranes. however, whereas prokaryotes only have internal regions where specialized structures and functions can occur (ex: nucleoid region containing the DNA of the cell), eukaryotes have additional internal membrane bound organelles that compartmentalize the cells * according to the theory of endosymbiosis a previously free living prokaryote (bacteria) was engulfed by another cell through endocytosis. after living together symbiotically for some time, the once free living prokaryotic lost its independent functionality and gave rise to either the mitochondria or chloroplast dependent on whether the prokaryote was anaerobic (mitochondria) or photosynthetic (chloroplast) * evidence supporting the evolution of the mitochondria + chloroplast via endosymbiosis includes the presence of the double membranes, circular DNA, and ribosomes in both these organelles

2.10 main concepts

* eukaryotic cells contain various membrane bound organelles including but not limited to the er, golgi complex, lysosome, mitochondria, and chloroplasts. these structures compartmentalize intracellular processes and enzymatic reactions which increase the efficiency of cellular function * internal membranes facilitate cellular processes by minimizing competing interactions and by increasing surface area where reactions can occur * loss of these intracellular compartments or changes to the unique internal surfaces and environments within the membrane bound organelles may hinder proper cellular function

2.8a main concepts

* external environments can be hypotonic, hypertonic, or isotonic to the internal environment of cells * water moves by osmosis from areas of low osmolarity/solute concentration to areas of high osmolarity/ solute concentration *growth + homeostasis are maintained by the constant movement of molecules across membranes * osmoregulation maintains water balance and allows organisms to control their internal solute composition

2.7 main concepts

* membrane proteins are required for facilitated diffusion of charged + large polar molecules through a cell membrane * large quantities of water pass through aquaporins * membranes become polarized by the movement of ions across the membrane * membrane proteins are necessary for active transport * metabolic energy (such as ATP) is required for active transport of molecules and/or ions across the membrane and to establish and maintain concentration gradients * the sodium/ potassium pump contributes to the maintenance of membrane potential

2.9 main concepts

* passive transport is the net movement of molecules from high concentration to low concentration without input of metabolic energy * water is transported in small amounts across the membrane by simple diffusion and in large amounts via facilitated diffusion through aquaporins embedded in the membrane * active transport requires the direct input of energy to move molecules from regions of low concentration to regions of high concentration * large molecules and large amounts of molecules are moved into the cell by endocytosis and are moved out of the cell by exocytosis

2.6 main concepts

* passive transport is the net movement of molecules from high concentration to low concentration without the direct input of metabolic energy * active transport requires the direct input of energy to move molecules from regions of low concentration to regions of high concentration * the selective permeability of membranes allows for the formation of concentration gradient of solutes across the membrane * in exocytosis, internal vesicles use energy to fuse with the plasma membrane and secrete large macromolecules out of the cell * in endocytosis, the cell uses energy to take in macromolecules and particulate matter by forming new vesicles derived from the plasma membrane.

2.4 main concepts

* phospholipids spontaneously form a bilayer in an aqueous environment with hydrophilic phosphate regions oriented towards the aqueous external or internal environment and the hydrophobic fatty acid regions face each other within the interior of the membrane * embedded proteins can be hydrophilic, which charge and polar side groups, and/or hydrophobic with non polar side groups and not charged * embedded proteins have a variety of functions which include transport, cell-cell recognition, enzyme activity, signal transduction, intercellular joining, and attachment to cytoskeleton + extracellular matrix * the fluid mosaic model consists of a structural framework of phospholipid molecules that are embedded with proteins, steroids (ex: cholesterol in eukaryotes), glycoproteins, and glycolipids that can flow around the surface of the cell in the membrane

2.1 main concepts

* ribosomes are NOT enclosed by a membrane and are subcellular components found in ALL forms of life, this reflects the common ancestry of all known life. ribosomes function to synthesize proteins for cells * eukaryotic cells have additional membrane-enclosed organelles that perform specialized functions for the cell. this includes the rough er, smooth er, golgi complex, mitochondria, lysosome, vacuole, and chloroplast

2.3a main concepts

* smaller cells have higher surface area - volume ratios and more efficient exchange of materials with the environment * surface area - volume ratio affects the ability of a biological system to obtain necessary resources, eliminate waste products, acquire + dissipate thermal energy, and exchange chemicals and energy with the environment * USING FORMULAS BE ABLE TO CALCULATE SURFACE AREA AND VOLUME

2.2 main concepts

* subcellular components and organelles interact to support cell function. the er, mitochondria, lysosome, and vacuoles all have specialized functions that occur within their membrane enclosed structures which increases the efficiency of the cell to perform chemical reactions and store materials * chloroplasts and mitochondria are structural features of eukaryotic cells that allow organisms to capture, store, and use energy. the folding of the inner membrane in both of these structures increases the surface area which allows for more ATP to be synthesized

2.8b main concepts

* the components of a graph include a title, correctly labeled axis with units, uniform intervals, identifiable lines or bars, and trend lines * the graph type is based on the type of data collection * graphs can be used to show trends over time, comparisons, distributions, correlations, variability in samples, and relationships between variables

2.5 main concepts

* the structure of cell membranes results in its selective permeability * cell membranes separate the internal environment of the cell from the external environment * selective permeability is a direct consequence of membrane structure as described by the fluid mosaic model * small nonpolar molecules such as nitrogen, oxygen, and carbon dioxide freely pass across the membrane * hydrophilic substances such as large polar molecules and ions move across the membrane through embedded channel and transport proteins * polar uncharged molecules including water pass through the membrane in small amounts * cell walls provide a structural boundary as well as a permeability barrier for some substances in the internal environment * cell walls of plants, prokaryotes, + fungi are composed of complex carbohydrates

2.8c main concepts

* water moves from areas of high water potential to areas of low water potential * water moves by osmosis from areas of low solute potential to areas of high solute potential * osmoregulation maintains water balance and allows organisms to control their internal solute composition/ water potential

components of effective graphs

- tittle: experiment details + what is being measured labeled axes with units - x axis (horizontal axis): independent variable - y axis (vertical axis): dependent variable -scaling: uniform intervals (large enough to analyze data, #'s on grid lines) - identifiable lines or bars: legend of label each line or bar - trend line: line of best fit that shows the general pattern or overall direction of the data

sodium-potassium pump

a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell it contributes to the maintenance of the membrane potential where three sodium are pumped and two potassium are pumped

example of osmoregulation

a freshwater paramecium is a single celled organism the environment is hypotonic to the paramecium which means it has more cellular solute andless cellular water water enters the cell via osmosis the paramecium is in danger or cell lysis except excess water collects in the contractile vacuole + is pumped out

channel proteins

a hydrophilic tunnel spanning the membrane that allow specific target molecules to pass through

fluid mosaic model overview

a moving phospholipid bilayer composed of varying types of molecules such as proteins, steroids, + carbohydrates the selective permeability is a direct consequence of the membrane's structure

enzymatic activity proteins

a protein built into the membrane may be an enzyme with its active site exposed to substances in the adjacent solution. in some cases, several enzymes in a membrane are organized as a team that carries out sequential steps of a metabolic pathway

scientific claim

a statement based off of evidence

solvent

a substance that dissolves the solute

solution

a uniform mixture of one or more solutes dissolved in a solvent

ratio of density of stomata per carbon dioxide concentration

a. the ratio decreases because fewer stomata are needed at a higher carbon dioxide concentration

which graph best represents the amount of starch, water, and glucose in the dialysis bag over the course of the investigation?

a. this graph shows the amount of glucose decreasing as the amount of water increases. this is the correspondent change of tonicity in efforts of the dynamic equilibrium of being isotonic. furthermore, the starch cannot diffuse thus it stays consistent throughout the experiment

which provided an unreliable estimate of the mean

a. treatment group ii has a lower than expected mean and that is the lowest standard of error of the mean * highest standard of error and lowest mean abundance in treatment group ii

active transport overview

active transport is the movement of molecules against their concentration gradient moves molecules and/ or ions against their concentration gradient, from low concentration to high concentration protein pumps are carrier proteins used in active transport requires metabolic energy such as ATP establishes and maintains a concentration gradient

active transport proteins

active transport moves molecules and/ or ions against their concentration gradient from low - high concentration it can use carrier proteins called pumps and REQUIRES metabolic energy (such as ATP) and establishes and maintains a concentration gradient

active transport

active transport requires the direct input of energy (such as ATP) to move molecules from regions of low concentration to regions of high concentration -> AGAINST concentration gradient

subcellular components universal to all cells

all living cells contain a GENOME + RIBOSOMES which reflect common ancestry in our common known life - all cells need to have mechanisms to store and pass along genetic information. nucleic acids + ribosomes work together to accomplish this goal

transport proteins

allow passage of hydrophilic substances across the membrane

ex one comparing # of trials, # drops of pure water, + # drops soapy water

bar graph

ex three elephants

as organisms increase in size their surface area - volume ratio decreases, this affects properties like the rate of heat exchange with the environment elephant bodies have little surface area but enormous volume (smaller ratio) = difficult to release heat from their bodies, because of this they have an adaption their large flat ears are the adaption. the flattened shape of the ear allows the elephant to dissipate more thermal energy as blood flows closer to the surface which allows the exchange and release of materials such as heat to become more efficient

representative relationships with biological molecules + effectiveness

as ratio goes up cell is more efficient + smaller smaller ratio is less efficient + bigger size increases = volume increases = less efficient size decreases = surface area increases + volume decreases = more efficient

attachment proteins for extracellular matrix or cytoskeleton

attach to the extracellular matrix and cytoskeleton, help support the membrane, can coordinate external and internal changes

mitochondria are found in most eukaryotic cells have their own DNA and ribosomes that are similar to those of prokaryotic cells. which of the following justifies the statement?

b. an ancestral cell most likely engulfed anaerobic prokaryote in a relationship that provided beneficial for both cells * theory of endosymbiosis in the origin of the mitochondria

what could be a proposal the scientists could use to determine if the cell use endocytosis to engulf the bacteria?

b. count the number of vesicles inside the cell before and after bacteria are added to the new water sample

rough er - golgi apparatus - vesicle

b. to synthesize and isolate proteins for the secretion or for use in the cell

isotonic solution

equal solute and water concentration = normal

describe characteristics of phospholipid membrane

be able to describe how the phospholipid bilayer contributes to the fluid mosaic models, different types of embedded proteins in it, + the addition of carbohydrates and lipids/ steroids to the existent phospholipids

predict cause + effect

be able to explain what would happen if part of the organelle function stopped working

comparison of cell compartmentalization in prokaryotic + eukaryotic cells

both cells have a plasma membrane that separates their internal environment from their surrounding environment - prokaryotic cells: they have an internal region called the nucleoid region that contains its genetic material - eukaryotic cells: they have an additional internal membranes and membrane bound organelles that compartmentalize the cell. genetic material is also contained in a membrane bound nucleus

relationship between functions of endosymbiotic organelles

both mitochondria and chloroplasts have double membranes, which function to regulate the passage of materials into and out of the cell and to maintain a stable internal environment *like prokaryotic cells; mitochondria and chloroplast both have their own circular DNA encoding genetic information and van reproduce through similar processes used by prokaryotes ( binary fission), and they both contain their own ribosomes that synthesizes proteins

some viral infections lead to the rupture of the lysosome, which prediction of the effect of this disruption of cellular compartmentalization is most likely correct?

c. hydrolytic enzymes will be released which would cause cell death * the interior of the lysosome is very acidic compared to the cytosol which would mean the cell wouldn't be able to maintain homeostasis or stable conditions thus having to program cell death through apoptosis

be able to calculate surface area to volume ratios

calculate individual surface area and individual volume. next divide surface area by volume. that is the ratio 1: x or x: 1 dependent on values used

establishing internal environment

cell membranes provide a boundary between the interior of the cell and its extracellular outside environment this allows the cell and cell membrane to control the transport of materials in and out of the cell

cell wall composition

cell walls are composed of complex carbohydrates * plant cell walls are composed of cellulose which is a polysaccharide * in fungi they are composed of chitin which is also a polysaccharide * in prokaryotes they are in a form called peptidoglycan which is a polymer consisting of sugar + amino acids

why are cells typically small?

cells are small because of moving materials (such as nutrients + waste) in an out of the cell gets more difficult the larger the cell is * cell size investigation lab. use three sizes of beet cubes soaked in bleach for 30 minutes since there was a higher concentration of bleach outside the cubes, bleach was able to move across the surface area of each cube

compartmentalization in eukaryotic cells

cells have a plasma membrane that allows them to establish and maintain internal environments that are different from their external environments eukaryotic cells have additional internal membranes and membrane-bound organelles that compartmentalize the cell cellular compartments allow for various metabolic processes and specific enzyme reactions to occur simultaneously increasing the efficiency of the cell - ex animal cells: mitochondria, er, lysosome, + golgi apparatus - ex plant cells: mitochondria, er, chloroplast, + golgi complex

origin of the chloroplasts

chloroplasts evolved from previously free living prokaryotic cells via ENDOSYMBIOSIS - a free living photosynthetic prokaryote was engulfed by another cell through endocytosis - the engulfed prokaryotic did not get digested by the engulfing cell; but rather each benefited from the arrangement - overtime, the engulfed cell lost some of its independent functionality and became the chloroplast of the eukaryotic cell

cholesterol + steroid components to fluid mosaic model

cholesterol is a type of steroid that is randomly distributed and wedged between phospholipids in the cell membrane of eukaryotic cells it helps regulate bilayer fluidity under different environmental conditions (in higher temperatures the cholesterol stabilizes the membrane and raises its melting point, and at lower temperatures it intercalates around the phospholipids which helps keep them from clustering maintaining the fluidity)

osmolarity

the total solute concentration in a solution - water has high solvency abilities (solvent + solute = solution)

selective permeability creates concentration gradients

concentration gradient: a concentration gradient is when a solute is more concentrated in one area than another a membrane separates two different concentrations of molecules always moves high - low concentration

if hormone secretion of a hormone secreted in response to reduced plasma volume is inhibited which of the following would result

d. the person would produce greater amounts of dilute urine

passive transport

diffusion: movement of molecules from high concentration to areas of low concentration - small nonpolar uncharged molecules (N2, O2, + CO2) pass freely - small amounts of very small polar molecules such as water pass freely facilitated diffusion: movement of molecules from high concentration to low concentration through transport proteins - large + small polar molecules + charged ions including sodium and potassium require channel proteins

carbohydrates in the fluid mosaic model

diversity + location of the carbohydrates and lipids enable them to function as markers - glycoproteins: one or more attached carbohydrate to a membrane protein (carbohydrates attached to an embedded protein) - glycolipids: lipids with one or more carbohydrate attachment

structure of plasma membrane in a nonaqueous environnment with a cytosol environment

e. hydrophilic heads facing towards the aqueous cytosol + hydrophobic tails facing towards non aqueous environment * this model best represents the plasma membrane because the phospholipid heads are oriented towards an aqueous environment AND the hydrophobic tails are oriented towards the non aqueous environment

integral proteins

embedded inside the membrane and span the membrane. they are also hydrophilic with charged and polar side groups on the ends when they interact with hydrophilic regions of the phospholipid bilayer. subsequently, they are also hydrophobic with non polar side groups penetrating the hydrophobic interior of the bilayer ex - transmembrane proteins

isotonic

equal concentrations of solute + solvent

isotonic solution (plant cell)

equal solute + water = flaccid

vesicles

essential to the function of the golgi complex, help transport proteins into the golgi apparatus to be later distributed outside of the cell or to other parts of the cell there are incoming transport vesicles + secretory vesicles vesicles: membrane containers that help move materials from one part of the cell to the other

prokaryotic vs eukaryotic cells

eukaryotic cells: the genome is enclosed in the membrane bound nucleus (distinguishing feature of eukaryotic cells), membrane bound organelles, larger, goes through mitosis or meiosis, and DNA is linear, and chromosomes are in pairs prokaryotic cells: no membrane bound organelles, only organelles include nucleus + ribosomes, smaller, naked DNA, round DNA, goes through binary fission, smaller, and singular chromosomes

be able to describe biological processes in the cell + what happens

ex: rough er - golgi complex - plasma membrane ex: vesicle containing macromolecule - lysosome - mitochondria

radioactively labeled amino acid best supported by results of the experiment

highest in mitochondria b. it was mostly incorporated in proteins that regulate and manage metabolic reactions

intercellular joining/ junctions

hook together various kinds of junctions, such as gap junctions or tight junctions

membrane proteins necessary for facilitated diffusion

facilitated diffusion: movement of molecules from high concentration to low concentration through transport proteins requiring channel + carrier proteins, aquaporin, or gated ion channel - large + small polar molecules need channel/ carrier proteins that get across the membrane - water in large quantities pass through aquaporins - charged ions such as sodium and potassium require the use of channel proteins

transport proteins (cell selective permeability)

hydrophilic substances move across the cell membrane using the help of transport proteins the two types are CHANNEL + CARRIER proteins small polar molecules like water can pass directly through the membrane but only in minimal amounts

Ψs = -iCRT

i = ionization constant (sucrose =1 , NaCl = 2) C = molar concentration (molarity = moles of solute/ volume of a solution) R = pressure constant (0.0831 L bars/ mol k) T = temperature in kelvin (temperature in celsius + 273 = kelvin)

dual y graph

illustrates the relationship between two dependent variables

solute potential of a solution

in an open system the pressure potential is zero so water potential is equal to the solute potential Ψs = -iCRT addition of solutes is equal to a more negative solute potential

osmoregulation in animal cells

in animal cells osmoregulation maintains water balance and allows control of internal solute composition/ water potential - shriveled, normal, + lysed

endocytosis (active transport)

in endocytosis the cell uses energy to take in macromolecules and particulate matter by forming vesicles derived from the plasma membrane - there are three types: phagocytosis, pinocytosis, + receptor mediated endocytosis

osmoregulation in plant cells

in plant cells osmoregulation maintains water balance and allows control of internal solute composition + water potential - plasmolysis, flaccid, + turgid

embedded proteins can be hydrophobic or hydrophilic

in the cell membrane there are embedded proteins can be hydrophilic or hydrophobic can either be PERIPHERAL proteins or INTEGRAL

osmoregulation in relation to water potential

increasing amount of solute in water - increase in solute potential, decrease in water potential increasing water potential - increase in pressure potential decreasing pressure potential - decrease in water potential *pressure potential + water potential DIRECT RELATIONSHIP *pressure potential + solute potential INVERSE RELATIONSHIP *water potential + solute potential INVERSE RELATIONSHIP

cell wall purpose

it serves as a structural boundary for the cell and permeable barrier not in animal cells - structural boundary: it protects and maintains the shape of the cell, prevents against cellular rupture when the internal water pressure is high, and helps plants stand up against the force of gravity - permeable barrier: plasmodesmata (small holes between plant cells that allow the transfer of nutrients, waste, + ions

relationship of surface area: volume

larger ratio = more efficient the cell is

environmental hypertonicity (plant cell)

less cellular solute and more cellular water = plasmolysis

environmental hypertonicity

less cellular solute and more cellular water = shriveled

hypotonic

less solute more solvent

ex two comparing molarity of sucrose in a beaker in relation to percent change in mass

line graph

peripheral proteins

loosely bound to the surface of the cell membrane and are hydrophilic with charged + polar side groups that allow them to interact with the hydrophilic region of the phospholipid bilayer

ex two small intestine

membrane folding increases surface area after chemical digestion occurs in the digestive tract and macromolecules are broken down into monomers - monomers need to be transported across the surface of the small intestine and into the bloodstream so they can get transported to cells and use those monomers for energy + do cell work modification: the outer lining of the small intestine is highly folding containing villi, each of the villi has additional microscopic projections called microvilli which further increases the surface area available for the absorption of nutrients. this makes the digestion process more efficient more folds = more efficient in transporting nutrients if conditions arise that lead to the loss of the folding the cells wouldn't be as efficient in absorbing nutrients for the organism

ex one root hair cells

membrane folding increases surface area root hairs on the surface of plant roots increase the surface area of the root (extended membrane), thus allowing for an increased absorption of water + nutrients

cell compartmentalization chloroplasts

membrane folding maximizes surface area for metabolic reactions to occur the thylakoids are highly folded membrane compartments that increase the efficiency of the light dependent reactions

cell compartmentalization mitochondria

membrane folding maximizes the surface area for metabolic reactions to occur electron transport + ATP synthesis occur in the inner mitochondrial membrane folding of the inner membrane increases surface area which allows for more ATP to be made

cell compartmentalization lysosomes

membrane minimizes interactions the hydrolytic enzymes of the lysosome function at an acidic environment by having this compartmentalization the inside of a lysosome can maintain a more acidic pH and allow for efficient hydrolysis to occur, while the rest of the cytoplasm can remain a more neutral environment

environmental hypotonicity

more cellular solute and less cellular water = lysed

environmental hypotonicity (plant cell)

more cellular solute and less cellular water = turgid

hypertonic

more solute less solvent

diffusion (passive transport)

movement of molecules from high concentration to low concentration - ex: small non polar non charged molecules like nitrogen, oxygen, + carbon dioxide

facilitated diffusion (passive transport)

movement of molecules from high concentration to low concentration through transport proteins allows for hydrophilic polar + ions to pass through cell membranes

passive transport

net movement of molecules from high concentration to low concentration WITHOUT metabolic energy such as ATP plays a primary role in the import of materials + the export of waste two major kinds of passive transport: DIFFUSION + FACILITATED DIFFUSION

ex four leaf stomata

organisms have evolved highly efficient strategies to obtain nutrients and eliminate waste the surface of the leaf has stomas. cells and organisms use specialized exchange surfaces such as these stomatal leave openings, to obtain molecules from and release molecules into the surrounding environment when the stomata are open carbon dioxide can enter the leaf, and water + oxygen can be released into the atmosphere

cell wall in osmoregulation

osmoregulatory mechanisms contribute to survival the cell wall helps maintain homeostasis for the plant in environmental hypotonicity osmotic pressure is high outside of the plant cell due to environmental hypotonicity water flows into the plant vacuoles due to osmosis causing the vacuoles to expand and press against the cell wall the cell wall expands until it begins to exert pressure back on the cell, pressure is called turgor pressure turgidity is optimal state for plant cells

osmosis + aquaporin

osmosis is the diffusion of water across a selectively permeable membrane large quantities of water move through aquaporins differences in relative solute concentrations can facilitate osmosis

phospholipids have both hydrophobic + hydrophilic regions

phospholipids are amphipathic (both hydrophilic + hydrophobic at the same time) hydrophilic phosphate head is polar hydrophobic fatty acid tail is non polar these phospholipids spontaneously form a phospholipid bilayer in an aqueous environment the hydrophobic tails are located on the interior of the bilayer interacting with each other in a hydrophobic way, and the heads are exposed to the aqueous environments inside + outside of the cell

overall structure of the cell membrane

phospholipids are amphipathic (both hydrophobic + hydrophilic) the hydrophilic phosphate head is polar the hydrophobic fatty acid tail is nonpolar they can spontaneously form a bilayer in an aqueous environment

brownian motion

random uncontrolled movement of particles in a fluid

receptor mediated endocytosis

receptor proteins on the cell membrane are used to target and capture specific target molecules to bring into the cell through a vesicle

exocytosis (active transport)

requires energy to move large molecules out of the cell in exocytosis internal vesicles use energy to fuse with the plasma membrane and secrete large macromolecules out of the cell these proteins include signaling proteins, or can be hormones or waste

line graphs

reveals the trends or progress over time for multiple groups or treatments tracks changes over time, concentrations, etc.

box + whisker plots

show the variability in a sample ideal for comparing distributions in relation to the mean

histogram

shows how values in a data set are distributed across evenly spaced or equal intervals explores the relationship between two or more variables

signal transduction proteins

signaling molecules create shape change in proteins, and proteins relay a message.

cell membrane selective permeability

small nonpolar and non charged molecules pass freely ex: nitrogen, oxygen, carbon dioxide hydrophilic substances such as large, polar, or charged molecules can NOT pass freely across the membrane

effect of surface area - volume ratios on exchange of materials

smaller cells typically have higher surface area - volume ratios and are MORE efficient in exchanging materials with the environment. ex: if the smaller cube would've been a cell it would've been more efficient in supplying internal demands such as taking in oxygen + nutrients and removing waste, co2, + heat as cells increase in volume the relative surface area decreases. this makes it difficult for larger cells to meet demands for internal sources to remove waste these limitations restrict the size and shape of a cell

example of active transport between ions

sodium channels open up and sodium diffuses across the membrane. then the potassium flows the other way due to the membrane potential and concentration gradient established this can also be accomplished through a sodium-potassium pump

explain how the cell is maintaining a high concentration of sodium in the environment surrounding the cell.

sodium ions are being actively transported from the inside of the cell to the outside of the cell through a membrane protein

cell-cell recognition proteins

some glycoproteins serve as identification tags that are specifically recognized by membrane proteins of other cells

carrier protein

spans the membrane and changes shape to move a target molecule from one side of the membrane to the other

smooth er

structure: does NOT have ribosomes attached to it function: responsible for detoxification (waste or drugs) and the synthesis/ creating of lipids

chloroplasts

structure: found in eukaryotic cells such as photosynthetic algae + plants, also has a DOUBLE MEMBRANE, contains two distinct compartments inside the THYLAKOID + STROMA contain... outer membrane (sift through particles entering chloroplast), inner membrane (less permeable + studded with transport proteins), grana (membrane compartments), stroma, and thylakoid 1) thylakoid: highly folded membrane compartments (grana), these membranes contain chlorophyll pigments that comprise the photosystems and electron transport proteins that can be found between photosystems embedded in the thylakoid membrane, light dependent reactions occur hear, and the folding of these internal membranes = increased efficiency/ surface area of reactions 2) stroma: fluid between inner chloroplast membrane and outside thylakoids, carbon fixation reactions occur hear (calvin-benson cycle) function: specialize in capturing energy from the sun and producing sugar for the organism (autotrophs) through the process of photosynthesis

mitochondria

structure: has a DOUBLE MEMBRANE (outer + inner membrane), the outer membrane is smooth, the inner membrane is convoluted forming curves = cristae this allows for more ATP to be made, double membrane provides compartments for different metabolic reactions, contains... matrix (the internal space where the krebs cycle occurs), intermembrane space (region in between the two membranes important in energetics + apoptosis), inner membrane (chemical barrier for nutrients), cristae (folds to increase surface area -> ATP synthesis), outer membrane (gateway to mitochondria) functions: production of ATP energy that eukaryotic cells can use for cell work *captures energy from macromolecules, the krebs cycle/ citric acid cycle occurs in the matrix, electron transport + ATP synthesis occur in the inner mitochondrial membrane

rough er

structure: has ribosomes attached to its membrane and compartmentalizes the cell function: associated with packaging the newly synthesized proteins made by attached ribosomes for possible export from the cell (to other parts of the cell or outside the plasma membrane) *carries out protein synthesis on ribosomes that are bound to its membrane

vacuoles

structure: membrane bound sacs found in eukaryotic cells function: storage of water and other macromolecules and can help the release of waste from a cell ex: plant cells have large central vacuoles (membrane contains water for cell) in plants vacuoles aid in the retention of water for turgor pressure (internal cellular force usually caused by water pushing up against the plasma membrane + cell wall) if the membrane is visible and small it means the plant is wilted/ flaccid while of the vacuole is large and filled it means the plant is full at turgor pressure and healthy

lysosome

structure: membrane enclosed sacs found in some eukaryotic cells that contain hydrolytic enzymes = chemical digestion contains... membrane (gateway to lysosome/ acidic b/c enzymes so needs to be protected), enzymes (hydrolytic enzymes = digestion of complex molecules), transport proteins (role of acidification to transport hydrolases + other digestive enzymes) function: chemical digestion, hydrolytic enzymes can be used to digest a variety of molecules such as damaged cell parts or macromolecules such as proteins or sugars *intracellular digestion, recycling of organic materials, or programmed death through apoptosis, can also break down and produce organic monomers

endoplasmic reticulum (er)

structure: network of membrane tubes in the cytoplasm of eukaryotic cells, two forms of er (smooth + rough) each plays a different role in cell function *structural differences between the rough er and the smooth er leads to functional differences between the two overall function: provides mechanical support (through network of membranes), plays a role in intracellular transport (shipping materials to parts of the cell)

golgi complex (golgi apparatus)

structure: series of flattened membrane bound sacs found in eukaryotic cells contain... secretory vesicle (involved in exocytosis), trans face (producing vesicles), cisternae (flattened sacs), lumen (cisternal space), cis face (substances entering from rough er), and incoming transport vesicles. function: involved in the correct folding and chemical modification of newly synthesized proteins and packaging for protein trafficking (shipping proteins to parts of the cell OR out of the cell aided by transport vesicles)

ribosomes

structure: two subunits (one larger + one smaller subunit) the ribosome's larger subunit is a polypeptide chain, and the mRNA connects this to the smaller subunit. both these subunits are not membrane enclosed. they are made of ribosomal RNA (rRNA) and proteins are NOT membrane bound organelles but found in both prokaryotic and eukaryotic cells *synthesize protein according to mRNA sequences function: they work to synthesize protein according to mRNA sequences and the instructions that are included in the mRNA sequence come from the cell's genome

volume

the amount of space the cell takes up

membrane polarization

the cell membrane allows for the formation of concentration gradients - electrochemical gradients rely on membrane potential which is an electrical potential difference (voltage) across a membrane membranes may become polarized by the movement of ions across the membrane

fluid mosaic model

the cell membrane is structured as a mosaic of protein molecules in a fluid bilayer of phospholipids the structure is not static and is held together primarily by the hydrophobic interactions which are weaker than covalent bonds this allows for most lipids and some proteins can shift and flow along the surface of the membrane or across the bilayer

pinocytosis

the cell takes in extracellular fluid containing dissolved substances " cell drinking "

phagocytosis

the cell takes in large particles " cell eating "

origin of the mitochondria

the nucleus and other internal membranes are theorized to have formed from the infoldings of the plasma membrane mitochondria evolved from previously free living prokaryotic cells via ENDOSYMBIOSIS - a free living aerobic prokaryote was engulfed by an anaerobic cell through endocytosis - the engulfed prokaryotic cell did not get digested by the engulfing cell; this arrangement became mutually beneficial - over time, the engulfed cell lost some if its independent functionality and became the mitochondria of the eukaryotic cell

results of beet + bleach experiment

the results showed a different amount of bleach inside each cube after 30 minutes. the smaller cube was more efficient in allowing bleach to enter as shown by the higher percentage of its total volume containing the bleach. cells need a sufficient amount of surface area for exchanging materials with its surrounding environment, this value can be quantified by calculating the surface area of the cubes.

solute

the substance being dissolved

effect of surface area - volume ratio

the surface area of the plasma membrane must be large enough to adequately exchange materials smaller cells typically have a higher surface area - volume ratio and MORE efficient exchange of materials with the environment as cells increase in volume the relative surface area decreases and the demand for internal resources increases (ex: taking in oxygen and nutrients, and taking out heat, waste, + co2) this creates the need for more complex structures to help aid the efficiency and adequately exchange materials with the environment

vesicles containing macromolecule - lysosome - mitochondria

the vesicles containing the macromolecule will fuse with the lysosome. the lysosome using its hydrolytic enzymes will break down the macromolecule into organic monomers. these monomers can be released from the lysosomes and transported to the mitochondria to be used as a source of energy

membrane proteins necessary for active transport

these proteins are called cotransport proteins

surface area of a cell

this is defined as the amount of surface covering the outer part of the cell.

cotransport proteins (membrane proteins for active transport)

this is secondary active transport that uses the energy from an electrochemical gradient to transport two different kinds of ions across the membrane through a protein - symport: two different ions are transported in the same direction - antiport: two different ions are transported in opposite directions

movement of large molecules into + out of the cell

this requires energy - endocytosis: the cell uses energy to take in macromolecules and particulate matter by forming new vesicles derived from the plasma membrane. different types include phagocytosis, pinocytosis, + receptor mediated endocytosis - exocytosis: internal vesicles use energy to fuse with the plasma membrane and secrete large macromolecules out of the cell

tonicity

tonicity is the measurement of the relative concentrations of solute between two solutions (inside + outside environment) internal cellular environments can be hypertonic, isotonic, or hypotonic to the external environments

types of transmembrane proteins

transport, cell-cell recognition, enzymatic activity, signal transduction, intercellular joining, + attachment for extracellular matrix/ cytoskeleton

osmosis

water moves by osmosis osmosis is the diffusion of free water across a selectively permeable membrane (large quantities of water move through aquaporins)

water diffusion in tonicity

water moves by osmosis into the area with a higher solute concentration water concentrations and solute concentrations are INVERSELY related water would diffuse out of a hypotonic environment into a hypertonic environment solutes diffuse along their own concentration gradients, from the hypertonic environment into a hypotonic environment

water potential

water moves from areas of high water potential to areas of low water potential the values of water potential can be positive, zero, or negative the more negative the water potential, the more likely water will move into the area ex: Ψ = -3 bars -> Ψ = -6 bars (water will move from inside the cell to outside the cell)

water moves by osmosis

water potential measures the tendency of water to move by osmosis calculated by pressure potential + solute potential Ψ = Ψp + Ψs Ψp - pressure potential Ψs - solute potential

water potential of pure water

water potential of pure water has a value of zero (0) in an open container Ψ = Ψp + Ψs Ψ = 0 + 0

tree is planted in soil with Ψ = -4 bars and the roots of the tree has Ψ = -8 bars. which direction will the water move?

water will move from the soil into the roots since the soil has a higher water potential than the roots

what would happen if the freshwater paramecium was placed in salt water?

water would begin to diffuse out of the paramecium because the cell is now hypotonic to the saltwater environment and the contractile vacuole would not fill. The cell is in risk of shriveling up.

isotonic enviornment

when a cell is in an isotonic environment a dynamic equilibrium exists with equal amounts of water moving in and out of the cell at equal rates NO net movement of water takes place

scatterplot graphs

x y graph scatter plot graphs are used to determine relationships between two different things compare two variables that may or may not have a linear relationship

water potential 0.5 m sucrose solution at 21 degrees celsius in an open system

Ψs = -iCRT Ψs = -(1)(0.5)(0.0831(273+21) Ψs = -12.2 bars