T/F Prokaryotes contain a plasma membrane
T
modern cell theory is based on a pattern and process
pattern: cells are the primary subunits of all life
-process: all cells are derived from existing cells
hypertonic definition in reference to water
low water concentration (thereby high solute concentration)
pinocytosis
when a cell drinks water in a phagocytic way
-can be facilitated diffusion by protein channels called aquaporins in the membrane
SM?
observation, question, research, hypothesis, experiment, data, conclusion
exocytosis
cells releasing proteins
what is endocytosis/phagocytosis?
when a cell appears to eat another
Hypotonic definition in reference to water
high water concentration (thereby low solute concentration)
relationship between solvent and solute?
inverse
-so if solute concentration is high, solvent concentration is low and vice versa
What is the result of no bonds between phospholipids of a membrane?
Lipids are in constant fluid lateral motion within the plane--fluid mosaic model that phospholipids are also made of types of protein
what makes fatty acids acidic?
carboxyl group on the end of the molecule
Fransesco Redi
maggots developed from flies meat in a jar experiment
-life comes from life
louis pastuer
disproved spontaneous generation of life through crane necked bottle experiment
Marcello Malpighi
doctorate of medicine and philosophy at the University of Bologna in 1653. He was the founder of microscopic comparative physiology and anatomy. Malpighi was also the first to describe microscopic structures of the kidneys, spleen, skin, and liver, to nam
robert hooke
micrographia
Unique about line graphs?
they are still continuous on x acis but have a discrete component in that several data are overlayed, superimposable
Continuous and discrete graphs?
continuous: no break in the scale on an axis
discrete: individually separate (categorical)
What is following paradigms
normal science
set in motion by a body of earlier research
______ argues a conclusion based on more general statements, or what are referred to as premises.
deductive reasoning
if the claim cannot be tested, it is not a ______
hypothesis
What is intervention / experimentation?
isolation of the subject where experimenters can change one variable at a time. Based on inductive reasoning.
What is systematic observation
Gathering of facts by sampling.
-Problem: what we see and what we perceive may be different (objectivity or impartiality is clouded by bias)
Four general methods that scientists employ to find the truth?
systematic observation, intervention or experimentation, hypothesis-making, and following paradigms
Define classification of membrane proteins: integral or transmembrane
span the entire membrane
-polar and nonpolar regions
-Ex: transport proteins
Define classification of membrane proteins: lipid-anchored
anchored to the membrane but don't span the entire length of said membrane
Define classification of membrane proteins: peripheral
associated (bound) with other membrane proteins
-does not interact with the membrane itself
-located on inside and out of membrane
What molecules does facilitated diffusion work with best?
Large molecules, polar, and ions
If the dimension is gallons, then the parameter must be____
volume
A high concentration of large water-soluble molecule is added to the fluid outside a cell. The cell will:
a. shrink and the fluid remaining inside the cell will become more concentrated
b. shrink and the fluid remaining inside the cell will become more di
A-the fluids can be made up of many other things besides water
A simple biological model for studying cell membranes involves forming red blood cell ghosts. These are formed by placing red blood cells in a solution that causes them to swell and burst open, releasing all of their cytoplasmic contents. Which of the fol
B
Which of the following substances would most likely require a protein to facilitate its diffusion across a cell membrane and into the cytoplasm?
A) water
B) oxygen gas (02)
C) glycerol
D) Na+
D-by both active or passive transport, depending on the direction of the concentration gradient.
--Moving with CG, passive
--Moving against CG, active
If the dimension in the study is meters, what is parameter?
length
Define dimensions
UNITS used to measure (m, kg, micro liters)
Define parameter
VALUE that was measured (height, volume, population size, concentration) --What it is that you are studying
T/F Prokaryotes have membrane-bound organelles
F
T/F Prokaryotes have a cell wall
T
T/F Prokaryotes have ribosomes
T
Function of the endomembrane system?
-Uses vesicles to transport proteins
-sorts proteins for secretion
Role of the nucleus?
provides instructions for protein synthesis and cell reproduction. Contains genetic information
General role of ER?
intracellular compartment that forms transport vesicles and participates in lipid synthesis and the synthesis of proteins
Role of golgi apparatus?
packages proteins for export from the cell and forms the secretory vesicle
Role of lysosomes?
digest worn-out organelles and cell debris; digest material taken up by endocytosis
Role of mitochondria
power house of cell, Sites of oxidative metabolism. Produce ATP
-membrane bound
Role of vacuoles
regulates water levels in plant cells
Role of peroxisome
used in the break down of fats and contains catalase enzyme
Small amphipathic __________ are the most abundant molecules in a membrane.
phospholipids
Larger _______ make up half of the mass of a membrane.
proteins
Polar _____________ are typically found attached to the outside of a membrane.
carbohydrates
Which of the following is true of the fluid mosaic model of membrane structure?
-Membranes behave more like a solid than a liquid.
-Lipids can flip from one leaflet to another as easily as they can move laterally in a membrane.
-Proteins can easily move a
Proteins can easily move laterally through membranes.
Aquaporin allows water molecules to move very rapidly across a plasma membrane. What would be the best definition of this process?
-facilitated diffusion using a transporter
-active transport using a transporter
-facilitated diffusion using a channel
-act
facilitated diffusion using a channel
Which of the following molecules are most likely to pass through the membrane by facilitated diffusion?
-H2O and sucrose
-H2O and O2
-CO2 and O2
-CO2 and H2O
H2O and sucrose (facilitated diffusion works best with large molecules, polar, and ions)
Who was Anton Leuvwenhook?
Designed the first microscope, used it to discover bacteria (from the plaque in teeth), blood, sperms.
Define fact
truth established through observation
Define hypothesis
tentative explanation or interpretation of data
-must be verifiable or falsifiable
-making a hypothesis is done based on deductive reasoning
Define law
A statement of a sequence of phenomena that is invariable under given conditions
Define theory
a reasoned explanation of facts or phenomena that serves as a basis of investigation to reach the truth. In science, theories are backed by substantial evidence.
An experiment was conducted to test whether protein X is produced in response to heat shock. Cells were divided into two groups, each with five samples. Group I was maintained at 37 �C. Group II was heated for 30 minutes at 45 �C. An assay for protein X w
A) Does heat shock alter the production of protein X in the cell?
B) Heat shock has "no effect" on protein x production
C) Cells at 37 C
An experiment was conducted to test whether protein X is produced in response to heat shock. Cells were divided into two groups, each with five samples. Group I was maintained at 37 �C. Group II was heated for 30 minutes at 45 �C. An assay for protein X w
what can you conclude questions" means stats calculations and then looking at error bars.
Steps:
1. Calculate the means and st. dev of each sample
---St. Dev is found by first taking the average and subtracting it from each value and squaring it each tim
Formula for SEM? (standard error of mean?)
SEM= sd/sqrt (n)
What does it mean if you are do 2 * SEM and your error bars overlap or do not over lap?
-DO overlap: no significant difference in data (p is high so fail to reject Ho)
-do NOT overlap: significant difference (p is low reject Ho)
What does OVERLAP mean?
no significant difference. P is high so fail to reject Ho
What does NO OVERLAP mean?
significant. p is low reject Ho
Define p-value
probability that Ho is true
If p-value > .05
-P is high, don't say byebye (to the Ho). Therefore...
-Fail to reject Ho, which is insignificant (meaning no significant difference)
---Any difference is likely due to chance
If p < or = .05 ...?
-P is low reject the Ho
-This is significant
-Accept Ha
What is a Type I error?
Ho is rejected when it is true.
P-value is probability of making this error
(false positive)
Type II Error?
Ho is accepted when it is actually false.
Probability of making this error= 1-p
(false negative)
Tay Sach's is an inherited disorder in which the nerve cells of the brain and spinal cord quit functioning due to a build up of cellular waste materials that normally are removed from the cell. Which organelle do you think is most likely impacted?
Lysosomes
You are the TA in a cell biology lab. At the end of the lab you found two unlabeled slides that you need to identify before storing them. You knew that students were working with animal and plant cells. As you look in the microscope. what structures can y
F. B and D
-Lysosomes (animal) and vacuole (plant)
-Chloroplast (plant) and centrioles (animal)
A simple biological model for studying cell membranes involves forming red blood cell ghosts. These are formed by placing red blood cells in a solution that causes them to swell and burst open, releasing all of their cytoplasmic contents. Which of the fol
hypotonic
You make a phospholipid bilayer with short, saturated hydrocarbon tails. You measure the permeability of this membrane to oxygen. You then double the length of the hydrocarbon tails, and re-measure membrane permeability. You then double the length of the
membrane permeability will decrease as the phospholipid tails can interact more with each other when they are longer
After we eat a large meal, our blood glucose levels are raised to high levels. That glucose is then taken up by some cells to be broken down and reduced to be used up as energy in between meals. Therefore, glucose levels are low in between meals. Glucose
Facilitated Diffusion
What are the four crucial questions in science?
QPRC
Q-what is the question
P-What was the protocol/method?
R-What was the result?
C-What is the conclusion?
What is the most important part of the scientific method and what is it based on?
The question
-based on observations and previous knowledge
-Answerable and lead to experiments
Define null hypothesis
no effect" --statistical hypothesis that one variable has no association with another or that experimental results do not differ from those that might be expected (i.e. the treatment will have no effect). Tests the null
Define alternate hypothesis
opposite of the no effect null, and what is actually being tested
Define independent variable
factors that the experimenter manipulates. X-axis on a graph
Define dependent variable
Response that is being measured. Y axis
Define negative control
either no treatment or a placebo is administered
-established that the observed effect was not due to a external factor
Define positive control
treatment is given to establish response and show the experiment will work
Mean
average=adding up the values / n
median
most middle # (resistant to outliers)
-put in order then take the middle (or average of middle numbers if n is even)
What is st. dev used for?
measure the average variation in a set of data
-Used to determine how far the subjects in the sample differ from the sample mean
What is standard error of the sample mean?
estimate of how far the sample mean is likely to be from the population mean
-times by 2 to increase CI to 95%
SEM=sd/sqrt n
What is the cell theory? (3 parts)
1. All living organisms are composed of one or more cells
2. cells are the smallest units of life
3. new cells comes only from pre-existing cells by cell division
Features of prokaryotes?
- Found within bacteria and archaea
-consist of a single membrane bound cell (w/cell wall)
-cytoplasm filled
-no sub-cellular compartments (no nucleus)
-cell motility is controlled by a flagella
Features of Eukaryotes?
-Much larger than prokaryotic cells w/smaller membrane-bound organelles
-Has compartmentalized organelles, which carry the following advantages;
---separation of incompatible chemical rxns
---increase efficiency of chemical reactions
Organelles common to all cells
-cytoplasm/cytosol
-cell membrane
-cytoskeleton
-ribosomes
What is the cytoplasm
-Gelatin like fluid that fills a cell
-constantly flows
-helps give the cell structure and aids in nutrient balance and transport within the cell
Role of the cell membrane
-protective layer around all cells
-allows food, O2, H2O into the cell, and waste out of the cell
DNA is _____ bound
membrane
Role of the ribosomes
-on RER
-cell's protein factories
-not membrane bound
Role of the cytoskeleton
helps the cell maintain or change shape. Made of protein
Organelles common to all eukaryotes
nucleus
nucleolus
mitochondria
endoplasmic reticulum
golgi apparatus
peroxisomes
centrosomes
Role of the nucleolus
-ribosomal rna synthesis
-ribosome subunit assembly
What is the ER
membrane channel system extending out from the nucleus
Role of the Rough ER
-Rough=ribosomes
-The ribosomes will synthesize proteins, and ER transports them to the golgi appartus
Role of the Golgi Apparatus
-protein modification and transport
Role of the smooth ER
-site of lipid synthesis
-metabolism of carbohydrates
-NO ribosomes
Role of the peroxisomes
Breakdown of toxins, organic molecules (AA, fatty acids), reduces radical oxygen species like hydrogen peroxide
-site of fat degradation
Role of centrosomes
city planning
Organelles exclusive to animal cells
lysosomes
centrioles
Role of the lysosomes
-Break down cell debris (including biopolymers)
-found only in animal cells
Role of the centrioles
-found only in animals cells
-helps cell divide
-housed in the centromere
-helps develop mitotic spindle fibers needed for cell division
Cell membrane is common within which of the types of cells?
prokaryotes, plant, and animal cells
Nucleus is common within which of the types of cells?
plant and animal cells
Proteins is common within which of the types of cells?
viruses, prokaryotes, plant cells, animal
mitochondria is common within which of the types of cells?
plant and animal cells
Ribosomes is common within which of the types of cells?
prokaryotes, plant cells, and animal cells
ER is common within which of the types of cells?
plant and animal cells
Cell wall is common within which of the types of cells?
prokaryotes and plant cells
Chloroplasts are _____ bound
membrane
Organelles unique to plant cells
large vacuoles, chloroplast, cell wall
Role of the cell wall
-only in plants
-protects and gives shape
Role of vacuoles in plant cells
stores water, food, etc.
-maintain turgor pressure
Viruses
-not living
-protein encapsulated DNA/RNA
-inject genetic material into host cell, which then replicates
-targets prokaryotes and eukaryotes
What is the plasma membrane?
-Separates life from nonlife
-Considered a mosaic of lipids, proteins, and carbohydrates
-Resembles fluid because lipids and proteins move
What is the cell plasma membrane made of?
-Phospholipid bilayer (amphipathic)
-hydrophobic: water fearing nonpolar faces in
-hydrophilic: polar region faces out
-Also proteins and carbohydrates make up the membrane
How are the individual phospholipid molecules organized?
-Polar (charged), hydrophilic head
-Nonpolar hydrophobic hydrocarbon tail
Small and nonpolar (ex. _______ ) molecules move across the phospholipid bilayer ______
Ex: O2, H2O, N2 (although water also moves across the membrane easily as an exception)
-quickly
Charged and large polar substances (ex. ______ ) cross the phospholipid ________
Ex. [most perm] glucose, sucrose > ions > amino acids, fatty acids [least permeable]
-cannot cross or move slowly
What are the factors that impact membrane permeability?
-Increase Permeability: more double bonds in hydrocarbon tail creates more kinks, shorter tail means less interactions and more permeable, temperature
-Decrease Permeability: Number of cholesterol molecules in the membrane
What is the only thing that decreases permeability in the phospholipid bilayer?
number of cholesterol molecules in the membrane & cold temperature
What 3 things increase permeability of the phospholipid bilayer?
1.more double bonds in hydrocarbon tail creates more kinks
2. shorter tail means less interactions and more permeable 3.temperature
What is the concentration gradient
Created by difference in solute concentration
-movement from high to low concentration
What is a solute?
the substance that is dissolved (like table salt)
what is a solvent?
substance that does the dissolving
(like water)
Define diffusion
spontaneous movement of molecules and ions from an area of high concentration to low concentration
-Form of passive transport (requires no energy)
What are transport proteins?
-Provide two examples
-Transport proteins are transmembrane proteins that provide a passageway for the movement of ions and hydrophilic molecules across membranes
-Channels and transporters (used for sugars, AA, nucleotides)
Define osmosis
diffusion of water across a selectively permeable membrane
-water diffuses from an area of more water to less water. Or low solute to high solute.
In osmosis, water moves from ______ SOLUTE concentration to regions of _______ SOLUTE concentration
moves from low solute concentration to high solute concentration
-this dilutes the higher concentration of water (solvent)
Define isotonic
equal water and solute concentrations on either side of the membrane
define hypertonic
solute concentration is higher (and water concentration is lower) on one side of the membrane
-water moves out of the cell and it shrinks (is concentration is higher on the inside and lower on the side) because it is hyper and "sweats
define hypotonic
If concentration is low in the cell this is hypo tonic. It will be like a hippo and swell up with water as water moves from a higher concentration outside of the cell to lower concentration in the cell
Define active transport and give two examples
Solute across a membrane against its gradient (from low to high)
-Requires energy
Examples:
1. Primary active transport: uses a pump and directly uses energy
2. secondary at: uses a pre existing gradient to drive transport