Unit 2 exam review Flashcards
Explain the fluid mosaic model
It is membranes that consist of a bilayer of phospholipids in which globular proteins are inserted.
What are globular proteins?
They are spherical shaped proteins.
List the 4 components of the cell membrane.
- Phospholipid bilayer 2. Transmembrane proteins 3. Interior protein network 4. Cell surface markers. (They tell the cell what to do)
What organic macromolecule is cholesterol?
It is a lipid.
Are phospholipids solid or fluid? Also explain phospholipids.
They are fluid. Individual phospholipids and unanchored proteins can move freely through the membrane. Saturated fatty acids make membrane more fluid than unsaturated fatty acids. Also warmer temperatures make it more fluid than cooler temps.
Name the 6 membrane protein functions.
- Transporters 2. enzymes 3. cell surface receptors 4. cell surface identity markers 5. cell to cell adhesion proteins 6. attachments to the cytoskeleton
List 2 facts about integral membrane proteins
They span the lipid bilayer or the transmembrane proteins. Also they are nonpolar domains so they are hydrophobic AA and are embedded in the hydrophobic regions of the lipid bilayer.
What do transmembrane domains do?
They span the lipid bilayer and they are a region of protein containing hydrophobic AA. Additionally, 7 is common.
What can Beta sheets form?
They can form a Beta barrel which is a cylinder.
What do Beta barrel do?
They regulate what goes in the cell.
Is passive or active transport diffusion?
It is passive.
What do channel proteins do?
They allow polar molecules to pass through
What do carrier proteins do?
They bind to a specific molecule and change shape so they can move through the pore and release the molecule.
What are the 2 types of channel proteins and what are they?
- ion channels, they allow the passage of ions that are associated with water. 2. Gated channels, they open of close in response to chemical or electrical stimulus(potential energy)
What is aquaporins?
It is water pores where osmosis moves water through towards hypertonic solution.
What are 2 things that active transport require?
It requires ATP or energy and it requires a specific carrier.
What three things do carrier proteins use in active transport?
- Uniporters, moves one molecule at a time 2. Symporters, moves 2 molecules at a times in the same direction. Usually one with active transport and the other with passive transport 3. Antiporters, they move 2 molecules in opposite directions.
Describe the Sodium-potassium (Na+-K+) pump.
It uses ATP, and it uses an antiporter. Sodium out, potassium in
What is coupled transport?
It is an active transport, uses energy released when a molecule moves by diffusion to supply energy for active transport. A symporter is used.
What are the three parts of endocytosis? Name and explain them
- Phagocytosis the cell takes in particular matter2. Pinocytosis the cell takes in fluid i.e. water. 3. Receptor-meditated endocytosis specific molecules are taken in after they bind to a receptor
What are three things to know about exocytosis?
- The vesicles fuse with the membrane and release their contents to the exterior. 2. used in plants to export cell wall material. 3. used in animals.
What is freeze fracturing?
It is a technique that separates the layers and reveals the membrane proteins using a scanning electron microscope (SEM).
What are photons associated with?
Light energy
What are two types of energy, and what do they do?
Kinetic energy, it is the energy in motion. Potential energy, it is the stored energy.
What is heat energy measured in?
Calories
What does one calorie equal?
Heat energy required to raise the temp of one gram of water by 1 degree c.
What is one kilocalorie(kcal) equivalent to?
1000 calories and 1 food calorie
Does oxidation in redox lose or gain an electron?
It loses an election
What does the first law of Thermodynamics state?
Energy can’t be destroyed nor created, only converted from one form to another.
What is an example of the first law of thermodynamics?
Sunlight energy to chemical energy through the process of photosynthesis which is an anabolic reaction.
What does the 2nd law of thermodynamics state?
Without external energy input all systems would get our of order
What is entropy?
It is the disorder of something
What is free energy?
It is energy available to do work, it is represented by G, which stands for Gibb’s free energy.
What is enthalpy?
It is energy contained in a molecule’s chemical bond
What is the equation for free energy?
Free energy=enthalpy-(temp X entropy) or G=H-TS or delta G = delta H- T delta S
What is delta G positive?
When products have more free energy than reactants, an example is light energy
What is delta G negative?
When reactants have more free energy than products, an example is cellular respiration
What is the turnover rate?
It is how many molecules of a substrate converts into product per second.
What are enzymes?
They are biological catalyst and are mostly proteins but can be RNA which would be ribosomes.
Do enzymes reactions have to be unnatural or natural?
They have to be natural
What is an endergonic reaction?
It is an “energy required” reaction that is positive delta G It is an anabolic reaction
What is an exergonic reaction?
It is an “energy yielding” reaction that is negative delta G. It is a catabolic reaction
What is the structure of ATP?
ribose (5 C sugar) adenine ( a nucleotide) and 3 phosphates
What is a substrate?
It is a molecule that will undergo a reaction. It is the reactant.
What is the active site?
It is a region of the enzyme that binds with the substrate
What is the pH in humans?
7.2 to 7.4
What is an inhibitor?
It is molecules that bind to the enzyme and decrease their activity.
What is a competitive inhibitor?
It competes with the substrate for binding to the active site. It has affinity.
What happens as the affinity increases?
It gets more tight and effective.
What is an allosteric inhibitor?
It binds to the site other than the active site. It changes shape therefore the function changes. It is the breaks.
What is an allosteric activator?
It is the gas. It binds to allosteric site to activate the enzyme.
What is anabolism?
It is an endergonic reaction that uses energy to make chemical bonds.
What is catabolism?
It is an exergonic reaction that breaks bonds and energy is released.
What are co-factors?
They are usually metal ions found in active site. Trace metals form the active site.
What are co-enzymes?
They are nonprotein organic molecules often used in a redox reaction as an electron donor or acceptor.
What are biochemical pathways?
They are a series of reaction in which the product of one reaction becomes the substrate for the next reaction.
What is feedback inhibition?
It is where it blocks the enzyme if you already have enough. It is the point of regulation or control.
What are the 3 multienzyme complexes in membranes?
- The product of one reaction is directly delivered to the next enzyme. 2. Unwanted side of reactions are reduced. 3. Reactions can be regulated as a unit.
Cristae is where?
It is in the inner structure of the mitochondria.
What are autotrophs?
They make their own food through photosynthesis. AKA glucose.
What are heterotrophs?
They eat others.
What do all organisms use to extract energy from organic molecules?
They use cellular respiration.
What is cellular respiration?
It is a series of redox reactions that result in the transfer of a proton.
What does NAD+ do and what does it accept to transform?
It is an electron carrier. It accepts 2 electrons and 1 proton to become NADH. (the reaction is reversible)
For every NADH we make how many ATP do we get?
3
What is the energy currency of the cell?
ATP
What is aerobic respiration?
The final acceptor is oxygen
For aerobic respiration how many ATP do we get for 1 glucose?
36
What is anaerobic respiration?
The final acceptor is an inorganic molecule (Not O2)
Describe fermentation.
It’s final acceptor is an organic molecule (lactate or ethanol(ETOH)) It is part of anaerobic.
How any ATP do we get for 1 glucose of fermentation?
2
What is the equation for cellular respiration?
It is C6H12O6+ 6O2 arrow to the right 6CO2+ 6H2O+ATP
What does delta G equal regarding kcal/mol of glucose?
-686
What is the main outcome in respiration?
It is to capture energy in ATP
What is the ETC and what does it do?
It stands for Election Transport Chains. It is where electrons are shuttled by electron carriers.
What is the formula for ATP?
ADP+ Pi arrow to the right ATP
What is Pi?
It is PO4-
What are 2 ways cells make ATP from ADP and Pi?
- Substrate -level phosphorylation, it is transferring a phosphate directly from another molecule (substrate) to ADP. 2. Oxidative phosphorylation, it is the use of ATP synthase enzyme and energy derived from a proton gradient to make APT, also called chemiosmosis.
What is ATP synthase?
It uses a proton gradient to produce ATP from ADP and Pi
List the 5 stages of oxidation of glucose?
- Glycolysis (cytosol) in mitochondria 2. pyruvate oxidation. 3. Krebs cycle 4. ETC 5. Chemiosmosis (ATP synthase and H+ gradient)
What goes in and out of glycolysis?
In: Glucose, 2 ATP, and 2 NAD+. Out: 2 ATP, 2 NADH and 2 Pyruvate.
What does the fate of pyruvate depend on?
O2 (oxygen) availability.
Where do the 5 stages take place?
Glycolysis is the cytoplasm. Pyruvate oxidation is in the mitochondria in eukaryotes or the cell membrane in prokaryotes. Krebs cycle is in the mitochondria. The ETC is in the mitochondrial inner membrane. The chemiosmosis is in also in the mitochondrial inner membrane.
For glycolysis to continue NADH must be regenerated to NAD+ by either what or what?
Aerobic respiration or fermentation.
What is Pyruvate oxidation?
It is oxidized when O2 is present to acetyl CoA which enters the Krebs cycle.
What does pyruvate dehydrogenase do?
It catalyzes the reaction in the mitochondria.
What goes in and out of Pyruvate oxidation?
In; Pyruvate, and NAD+ Out: 1 CO2, 1 NADH 1 acetyl-CoA (2 carbons)
What goes in and out of the Krebs cycle
In: Acetyl CoA, oxaloacetate, 3 NAD+, 1 FAD, and ADP+ Pi. Out: Co2, 3 NADH, 1 FADH2 and 1 ATP
How many ATP does FADH2 yield?
It yields 2 ATP
What happens for glucose in the Krebs cycle?
You double it.
What is a proton gradient?
Results from higher concentration of protons outside the inner membrane of the mitochondria than inside the membrane.
When dealing with no O2, and fermentation what are the 2 things and which releases CO2?
Ethanol fermentation and lactic acid fermentation. Ethanol fermentation releases CO2.
What does phosphofructokinase do?
It runs glycolysis.
What inhibits pyruvate dehydrogenase enzyme?
NADH
What inhibits citrate synthetase enzyme ( part of Krebs cycle)?
ATP
Difference between Calories and calories.
Calories (Big C) is to get 1 kilo of water up 1 degree c. calories (small C) is to get 1 gram of water up 1 degree c.
What goes in and out of ETC/chemiosmosis?
In: 10 NADH, 2 FADH2, and 4 ATP. Out: 38 ATP and a proton gradient
What is the formula for photosynthesis?
6CO2+ 6H2O arrow to the right C6H12O6+ 6H2O+ 6O2.
What does non-oxygenic mean?
Non oxygen producing
What tends to be abundant in plants?
Chloroplasts
In plant cells what are the specialized leaf tissues called?
Parenchyma or Mesophyll.
Where does light dependent reactions take place?
In the thylakoid membrane.
Where do dark reactions take place?
In stroma of the chloroplast.
What do you need water for regarding protons and electron?
protons proton gradient, and electrons, for light energy.
What are two things Thylakoids contain?
Chlorophyll and accessory pigments.
What is chlorophyll considered?
A funnel.
What does the shorter wavelength equal?
Higher energy.
What is the photoelectric effect?
It is where the electrons get excited by being heated up.
What do pigments do?
They are molecules that absorb and reflect light.
What is the absorption spectrum?
It is the range and efficiency of proton absorbance.
What is chlorophyll A?
The primary photosynthetic pigment in plants and cyanobacteria It absorbs violet- blue and red light and appears yellow green
What is chlorophyll B?
A secondary or accessory pigment. It absorbs wavelengths that chlorophyll A does not absorb well. It appears blue- green. It gives energy to A.
What is a porphyrin ring?
It is a ring with alternating double and single bonds with Mg in the center.
What does a photosystem consist of?
Antenna complex, which is 100s of accessory pigment molecules. Also a reaction center which brings electrons alike and supercharges them.
What is an electron donor?
Water
What is the significance of chlorophyll A?
It is the key to it all.
What is P680?
It is photosystem 2
What is P700?
It is photosystem 1
What is the P in NADPH?
Phosphate group.
What does NADPH sponge?
Electrons and protons
What is grana?
A stack of thylakoids.
What is the stroma?
It is a liquid matrix that surrounds thylakoids, and is the sight of dark reactions.
What goes in and out of light dependent reactions?
In: H2O, CO2, and sunlight. Out: ATP and NADPH.
What goes in and out of light independent reactions (dark)?
In: CO2, ATP, and NADPH. Out: G3P/Glucose and O2
Where does light reactions occur?
In the Thylakoid membrane.
Where do dark reactions occur?
In the stroma of a plant’s cell chloroplast.
How do you spell that acid?
Crassulacean acid
What is the first step of the “Z” scheme?
The hydrolysis of water
Where does the shot of energy come from regarding the “Z” scheme?
Protons alike
Where are some non-oxygenic bacteria?
Near thermal vents
In some non-oxygenic bacteria a single photosystem is used in what?
Cyclic photophosphorylation
What is an interesting fact about Cyclic photophosphorylation?
The “Z” scheme evolved from it
Electrons are returned to what through an ETC?
Bacteriochlorophyll
What are three things cells need to build carbohydrates?
- Energy (ATP molecules) 2. Redox potential (NADPH molecules) 3. Source of carbon (CO2 gas)
What is rubisco?
An enzyme that takes RuBP and puts carbon on it
For every 6 molecules of CO2 how many G3Ps leave the cycle?
2 G3Ps
What are the two rubisco enzymatic activities?
- Carboxylation which is good. The addition of CO2 to RuBP. Favored under normal conditions. 2. Photorespiration which is bad. It is the oxidation of RuBP by oxygen. It is favored in hot conditions and causes a loss of carbon.
Describe C3 and C4 plants.
C3 are like lettuce and in the mesophyll. They can not store carbon and are better in cooler weather. C4 are like cactus and dandelions. They are can store carbon and are better in the heat. They are in the Bundle dean (Something like that).
What are CAM plants?
They are where the stroma only opens at night and they store CO2. The Calvin cycle during the day and the stromata at night. An example is pineapple
