Midterm 2 Flashcards
(242 cards)
1
Q
What kind of bond is formed between water molecules?
A
Hydrogen bonds
2
Q
What’s cell theory?
A
All living organisms are made of cells
3
Q
What are the elements of life and why are they so important?
A
- Oxygen
- Carbon
- Hydrogen
- Nitrogen
- They’re the building blocks of molecules that are essential for life
4
Q
Which atom is the basis of every biological molecule?
A
- Carbon
- Life is said to be “carbon-based”
5
Q
What are elements?
A
- Chemically pure substance that cannot be broken down
- Elements are made of one type of atom
6
Q
Which element is said to be a friendly atom?
A
Hydrogen because it interacts with everyone
7
Q
Which element is said to be a noble gas?
A
Helium because it doesn’t interact with anyone
8
Q
What are atoms made up of?
A
- Protons
- Neutrons
- Electrons
9
Q
What does the nucleus of an atom contain?
A
It contains protons and neutrons
10
Q
What kind of charge do protons have?
A
Positive charge
11
Q
What kind of charge do neutrons have?
A
No charge
12
Q
What kind of charge do electrons have?
A
Negative charge
13
Q
What kind of mass do protons have?
A
Mass of 1 amu
14
Q
What kind of mass do electrons have?
A
Mass of 0 amu
15
Q
What kind of mass do neutrons have?
A
Mass of 1 amu
16
Q
Where are electrons located?
A
In the orbitals or energy shell
17
Q
What’s the octet rule?
A
We always need to worry about whether there are 8 electrons in the shells
18
Q
Isotopes of each element vary in what?
A
The number of neutrons
19
Q
What happens if 2 atoms collide with each other?
A
They may form a chemical bond which will fulfill their need of having their outer energy shelled
20
Q
How do elements fill their valence shells?
A
They gain or lose electrons to acheive a stable electron configuration
21
Q
Which elements have a stable electron configuration because they have a full outer or valence shell?
A
- Helium
- Neon
- Argon
22
Q
What do the electrons in the outermost shell determine?
A
The atom’s energetic stability and tendency to form chemical bonds with other atoms
23
Q
What’s a covalent bond?
A
- Sharing of electron pairs
- Can be very strong
- Ex: H2O
24
Q
What’s a hydrogen bond?
A
- Sharing of an H atom
- Is strong
- Individually they’re very weak but together they’re very strong
25
What's an ionic bond?
- Attraction of opposite charges
- Strong
- Ions are most stable when they can pair up with another ion (of opposite charge) and form a neutral molecule
26
What's a hydrophobic interaction?
- The interaction of nonpolar substances in the presence of polar substances
- Weak
27
What kind of reaction forms molecules?
- Chemical reactions
- They can also break down molecules
28
What do chemical reactions do?
They convert reactants into a product -> synthesis of molecules
29
Which bonds are strong in water and which aren't?
- Covalent bonds = strong in water
- Ionic bonds = weak in water, they can change in water
30
Hydrogen peroxide and water are what?
Compounds (composed of at least 2 different elements)
31
What's a double covalent bond?
- Ex: O = O
- By sharing 2 electrons elements fulfill the octet rule
32
What kind of covalent bond does a polar molecule have?
A polar covalent bond
33
Can atoms be polar?
No, only molecules can be polar
34
How do ionic bonds form?
- By electrical attraction
- The more electronegative (en) atom steals an electron
35
Water is made up of what kind of bonds?
Hydrogen bonds
36
What are the rules of attraction for hydrophilic and hydrophobic interaction?
- Hydrophilic interaction = polar + polar
- Water is polar so polar molecules are attracted to water
- Hydrophobic interaction = non-polar + non-polar
- Nonpolar molecules are more attracted to one another than to water
37
What's water's temperature capacity like?
Water has a high heat capacity
38
What are the properties of water?
- It has high heat capacity
- It has high heat of vaporization
- It's an awesome solvent
- Water is cohesive (water molecules stick to each other - surface tension - insects can glide on water)
- Water is adhesive (stick to other molecules - drinking out of a straw)
39
What's a partial charge?
A charge that influences atomic interactions
40
How do the bonds in water define its form?
- Gaseous water -> not a lot of bonds
- Liquid water -> more bonds
- Solid water -> a lot of bonds
41
What do unstable ions do to make themselves stable?
By forming ionic bonds
42
What's the relationship between protons and electrons in atoms?
- Each electron has a negative charge equal to the proton's positive charge
- In uncharged, neutral atoms, the number of electrons orbiting the nucleus is equal to the number of protons inside the nucleus
43
What's a forward reaction?
- It's a synthesis reaction
- Consists of building a molecule from reactants (can be reversible)
44
What's a decomposition reaction?
Consists of breaking down a molecule into its component parts
45
What's the dehydration synthesis reaction?
- It combines monomers to make polymers, water is released
- Dehydrating the product/reactants to produce a product in water
- One of the products is always water
46
What's a peptide bond?
- When 2 molecules that make up a protein collide, they will form a chemical bond called peptide bond
- The bonding of a Nitrogen and Carbon molecule
47
What are 2 major categories of macromolecules?
- Carbohydrates
- Proteins
48
What's a Glycosidic bond?
Where Glucose and Fructose come together and make Sucrose (table sugar) -> reaction that has to happen to have sugar
49
What's the hydrolysis reaction?
It breaks down macromolecules into subunits
50
What's the function of enzymes?
They are specialized proteins that reduce the amount of energy that’s needed to break or build a bond
51
How do enzymes help with the dehydration synthesis and the hydrolysis reactions?
- Dehydration synthesis and hydrolysis reactions are slow so and enzymes speed up the reaction
52
What's the basic unit of a carbohydrate?
(CH2O)n
- Where n = number of carbons in the molecule
53
What's the covalent bond between monosaccharides called?
A glycosidic bond
54
What would happen if we didn't have enzymes?
Every reaction in the body would happen when it could and not when needed
55
What do polysaccharides do with regards to monosaccharides?
They "store" monosaccharides
56
Which organism usually has unbranched polysaccharides?
Plants - > starch
57
What two organisms have branched polysaccharides and what are these called?
- Animals: Glycogen
- Plants: Amylopectin
58
What's Glycogen?
Readily accessible stored energy that can be accessed when we’re exercising and aren’t able to eat (storages of energy)
59
What are the 3 types of lipids?
- Fats
- Steroids
- Phospholipids
60
What are lipids?
- Comprised of fats, steroids and phospholipids
- They are all hydrophobic and insoluble in water
61
What is the function of fats?
Primarily used for metabolism
62
What's the function of steroids?
They form vitamins and hormones
63
What's the function of phospholipids?
They form cell membranes
64
What 2 things combine together to form a fat?
Glycerol and Fatty acids
65
What are the 3 different types of fats?
- Saturated fatty acids
- Unsaturated Trans Fats
- Unsaturated Cis Fats
66
What's matter?
Any substance that occupies space and has mass
67
What are Saturated fatty acids?
- Bad for humans -> increase risk of heart disease
- Increases cholesterol
- Aren't good for anything besides storing energy
- Found in bacon
- Have no double bonds, so no kinks or bends in them...only single bonds
- Solid at room temperature
68
What are Unsaturated Trans fats?
- Less dangerous for humans because they bend a bit and change their shape
- Called trans because of the 2 hydrogen atoms on inside and outside are opposite to each other
69
What are Unsaturated Cis Fats?
- Better for humans because they have a bent configuration
- Called cis because the 2 hydrogen atoms in the middle are on the same side
- High omega-3
- The more cis unsaturated fat you have in something the more liquid it’ll be
- Moderate intake can reduce risk of heart disease
70
What kind of fat do you want for better health?
- Polyunsaturated cis fats
- A type of Unsaturated cis fat
71
Why do marine animals have fat in their fur and feathers?
Because fats are great for insulation -> keep animals warm in the cold water
72
What are phospholipids?
- They're amphipathic molecules composed of saturated and unsaturated fats
- They have hydrophilic heads (made up of Diacylglycerol and Phosphate) and hydrophobic tails (made up of fatty acids)
73
What is the amphipathic property of phospholipids essential for?
It's essential to form cellular membranes
74
What are cellular membranes comprised of?
Phospholipid bilayers
75
What is the steroid of Cholesterol useful for?
Cholesterol is a precursor for the synthesis of hormones and vitamins
Ex of hormones:
- Estrogen
- Testosterone
Ex of vitamins:
- Vitamin d3
You need Cholesterol in your diet or else you can throw off a hormonal imbalance
76
What are nucleic acids?
DNA & RNA
77
Describe DNA (function, location, structure, sugar)
- A polymer of nucleic acids
- It's all the information that's needed to build a cell
Function: Carries genetic information
Location: Remains in the nucleus
Structure: Double helix
Sugar: Deoxyribose
78
Describe RNA (function, location, structure, sugar)
Function: Involved in protein synthesis
Location: Leaves the nucleus
Structure: Usually single-stranded
Sugar: Ribose
79
What are the pyrimidines of DNA?
Cytosine and Thymine
80
What are the purines of DNA?
Adenine and Guanine
81
What are the pyrimidines of RNA?
Cytosine and Uracil
82
What are the purines of RNA?
Adenine and Guanine
83
All cells have DNA and RNA, but not all cells have a ___?
Nucleus
84
What are nucleic acids built from?
- Nucleotide subunits
- 1 phosphate base and a sugar backbone
85
What's a double helix?
two anti-parallel DNA molecules linked together by hydrogen bonds
86
What are the bonds that form the structure of a DNA molecule?
- For the backbone (phosphate and sugar): Covalent bonds
- For the rungs (A/G and T/C): Hydrogen bonds
87
What's the pairing rule in a DNA molecule?
- The purines link with the pyriminides (A with T and G with C)
- It's a ratio: if you know the amount of A and the amount of G, you can figure out the amount of T and C
88
What are the different types of proteins?
- Digestive enzymes (amylase and pepsin)
- Transport (hemoglobin)
- Structural (tubulin and keratin)
- Hormones (insulin and thyroxine)
- Defense (immunoglobulins)
- Contractile (actin and myosin)
- Storage (legume storage proteins and egg whites)
89
What are proteins made up of?
- Proteins are polypeptides
- Made up of amino acids
90
How many different amino acids are there?
There are 20 different side groups so 20 different amino acids
91
What are the 3 different types of amino acids?
- Nonpolar (ex: Glycine)
- Polar (ex: Glutamine)
- Electrically charged
92
Which types of amino acids are hydrophobic and which ones are hydrophilic?
- Nonpolar amino acids = hydrophobic
- Polar and electrically charged amino acids = hydrophilic
93
What are the two types of electrically charged amino acids?
- Acidic (ex: aspartic acid)
- Basic (ex: Lysine)
94
What are the structures of non-polar amino acids?
- Amino acids have a hydrocarbon side-chain
- Exception: Glycine
95
What are the structures of polar amino acids?
Polar amino acids have side-chains with either:
- partial charge
- net positive charge
- net negative charge
96
What's a peptide bond?
- A type of covalent bond
- A polypeptide of more than 2 amino acids linked together
- Peptide bonds are the only thing that can be recognized by a giant enzyme in cells to form proteins
97
What's a polypeptide?
- A polymer of amino acids
- A protein is a folded polypeptide
98
What's the primary protein structure?
A sequence of a chain of amino acids
99
What's the secondary protein structure?
Hydrogen bonding of the peptide backbone causes the amino acids to fold into a repeating pattern (Beta pleated sheet or Alpha helix)
100
What's the tertiary protein structure?
3-dimensional folding pattern of a protein due to side chain interactions
101
What's the quaternary protein structure?
Protein consisting of more than one amino acid chain
102
What could happen if you mutate one of the amino acids?
- You can create a change in gene
- Creates a huge change in the protein and the cell
- This could cause diseases such as sickle cell anemia
103
What's sickle cell anemia?
- Caused from changing amino acid from acidic to non-polar
- Hemoglobin is very necessary (necessary for carrying oxygen to the lungs)
- This disease changes shape in hemoglobin and changes shape of cell
104
What does potential energy mean?
- When objects are at rest
- Ex: Mass and gravity
105
What does kinetic energy mean?
- When objects are in motion
- Ex: Velocity
106
What are the 5 types of energy?
- Potential
- Kinetic
- Chemical
- Radiant
- Thermal
107
What's an example of chemical energy?
Chemical bonds and ATP
108
What's an example of radiant energy?
Sunlight (photosynthesis)
109
What's an example of thermal energy?
Sunlight (thermal regulation)
110
What do producers (ex: plants) do with radiant energy?
They will transform things like radiant energy into chemical energy
111
What are producers?
Plants
112
What are consumers?
Animals
113
What are decomposers?
- Fungi
- Bacteria
- Worms
114
What's energy flow?
It's basically order at the expense of the universe
115
What's a Joule?
- It measures the amount of heat required to raise temperatures of water
- It measures the energy required to vertically lift an object
- Its measures the energy released when that same object falls back
down to the ground
116
What's a calorie?
-The amount of energy required to raise the temperature of water
- Unit of energy represented on food labels
- Consumed by cells to do work
- Extra calories can be stored as fat
117
What's the metabolic rate?
The rate at which the body uses energy
118
What are the 2 major types of energy we consider?
- The potential energy of objects at rest
-The kinetic energy of objects in motion
119
What's chemical potential energy?
- It exists between atoms in a molecule, and can be released to perform work, such as catalyzing a chemical reaction
120
What do chemical reactions require?
Collisions
121
As the temperature drops, what happens to the probability of collisions to happen?
It goes down
122
What's energy?
- Energy is defined by the ability to do work
(Gibbs free energy; G)
Ex: breaking a bond, making a bond, moving particles, etc.
123
What's the 1st law of thermodynamics?
- Its states that energy can be neither
created nor destroyed (conservation of energy)
- Energy can change forms, and energy can
flow from one place to another
- A particular consequence of the 1st law is that the
total energy of a “closed” system does not change
124
What does order require?
Energy transfer
125
Describe the equation of Gibbs free energy and heat
Change in free energy (energy released used to do work) = Change in enthalpy (change in order - increase in order within the system) minus Temperature times Change in entropy (change in disorder - decrease in order within the system)
126
What's the 2nd law of thermodynamics?
- Energy transfer is not 100% efficient
- Entropy cannot be transformed into useful energy
127
True or False? The change in free energy can only be greater than 0
False. The change in free energy can be greater than or less than 0
128
What has to happen for the change in free energy to be less than 0?
- If the reaction breaks atoms apart, the change in entropy is large (∆S>∆H) and releases free energy to perform work
129
What has to happen for the change in free energy to be more than 0?
The reaction bonds atoms together, the change in enthalpy is large (∆H>∆S) and potential energy is stored rather than released
130
What's an exergonic reaction?
- When the change in free energy is less than 0 (∆G < 0)
- Change in entropy is large
- This is a spontaneous reaction because the reactants have more free energy than the products
- With this reaction, energy is released
- Example of breaking a chemical bond
131
What's an endergonic reaction?
- When the change in free energy is more than 0 (∆G > 0)
- Change in enthalpy us large
- This is not a spontaneous reaction because you have to put a lot of chemical energy into it since the reactants have less free energy than the products
- With this reaction, energy is added
- Have a very high energy barrier
- Example of forming a chemical bond
132
What kind of energy requirement do both exergonic and endergonic reactions have?
Because of the transition state, they both have an activation energy requirement
133
What's the transition state?
A state where the atoms are being pulled on in some way
134
For humans to work, where does free energy have to be?
It has to be around 0 constantly
135
What does energy transfer do in our bodies?
- Changes the shape of proteins and structures within our cells
- Creates machines
- Moves chromosomes
- Makes cells crawl when going through the blood looking for a virus to engulf
136
How do enzymes work with chemical reactions?
- They facilitate them
- Enzymes can make or break a bond
137
What's the organism's metabolism?
All the chemical reactions of an organism
138
What are 2 metabolic pathways?
- Anabolic
- Catabolic
139
What's the anabolic pathway?
- Pathway where small molecules assemble into large ones
- Energy is required
140
What's the catabolic pathway?
- Pathway where large molecules break down into small ones
- Energy is released
141
What's cellular respiration?
A series of chemical reactions that transform chemical energy stored in glucose into chemical energy stored in ATP
142
What does ATP consist of?
- Adenine
- A sugar
- 3 phosphate groups
143
How do you use the stored energy of ATP?
You have to break a bond which releases energy
144
What are the 2 functions of enzymes?
1. They can bind the reactants and they like to bind them
2. They’re specialized for breaking ATP down into ADP and using that chemical energy to perform the work needed to catalyze the reaction that’ll turn the reactants into a product
145
What are different kinds of work ATP can do in the cell?
- Mechanical work -> cell motility
- Transporting a solute across a membrane against a concentration gradient
- Chemical work -> breaking/making bonds by changing shape of enzyme
146
What's an example of ATP acting as a transport of a solute across a membrane against a concentration gradient?
Sodium-Potassium Pump
147
What's an energy barrier?
- If a molecule needs to break a bond, it'll force its atoms apart to break the bond which produces an unstable state
- Energy is hence needed to get to a new stable state (products)
- Without energy barriers, everything would break apart
148
What does a catalyst do with the amount of free energy required for a chemical reaction, such as the activation energy needed to get past the transition state?
- It reduces it
- The activation energy to get past the transition state is reduced by an enzyme
149
What's phosphorylation?
When a phosphate group is transferred from ATP to a enzyme
150
How is ADP produced?
When a phosphate group is transferred from ATP to a enzyme (phosphorylation), that energy can be used to lower activation energy
151
What would transferring chemical potential energy to an enzyme through ATP do?
It'll allow it to generate this transition state that’s necessary for the chemical reaction to occur
152
What's the active site?
It's where the substrate binds to the enzyme
153
What do enzymes do with substrates?
They change them into products
154
What's an induced fit (with enzymes)?
- The binding of the substrate and the enzyme is an induced fit and once the reaction is catalyzed, the products don’t fit into the enzyme anymore
- This is dependent on potential chemical energy
155
What do enzymes do and what to they not do?
- Enzymes speed up the rate of a reaction (or product production) by reducing the energy needed for the reaction to occur
- Enzymes do not create reactions that would not occur in their absence, they just speed them up
156
What would happen if there were no enzymes?
- Everything would happen at the rate that it could occur thermodynamically which might either be too fast or too slow for survival
- Everything would be determined by temperature, due to everything being based on collisions (diffusion)
157
What's the degradation reaction?
Using PO4 (phosphate) to break a bond rather than water (H20)
158
What does cell theory state?
1. All living organisms are composed of one or more cells
2. The cell is the basic unit of structure and organization in organisms 3. Cells arise from pre-existing cells
159
What kind of molecules are the essential building blocks of the macromolecules of living organisms
Organic molecules
160
How did the synthesis of organic molecules happen?
Inorganic molecules and water combined with radiant energy
161
What could organic molecules be?
- Amino acids
- Carbohydrates
- Nucleic acids
- Organic acids and bases
162
What evolved first, RNA or DNA?
RNA
163
What was the first cell?
Self replicating RNA enclosed in a phospholipid membrane
164
Why did the first cell have a phospholipid membrane
As a way of isolating chemicals from the environment
165
What's volvox?
A unicellular organism with specialized cells
166
What does unicellular mean?
Means they're capable of living independently
167
What happens as a cell increases in size?
- Its surface area-to-volume ratio decreases
- Surface area is key to the exchange of energy with the environment
168
What are prokaryotic cells and what are they comprised of?
- Evolved first
- Bacterial cell
- Has a cell membrane, cell wall, ribosome, chromosome (DNA) and flagellum
- Doesn't have a nucleus, mitochondria or vacuole
169
What are eukaryotic cells and what are they comprised of?
- An animal or plant cell
- Has a nucleus, mitochondria, microtubules, microfilamenta, plasma membrane, cytoplasm, vacuole
170
Why are plant cells different from animal cells?
- They have chloroplasts (similar to mitochondria)
- A central vacuole
- A cell wall
171
Why are cells said to be tiny ecosystems?
Because they're adapted to their environment and lifestyle
172
What's the function of the plasma membrane?
- A barrier between the cell and the environment
- It’s based on the phospholipid bilayer
- It has cholesterol
- It's adaptable (can be folded up to fit the surface area)
173
What's the function of the nucleus?
- Contains a library of information needed for cellular function
174
How is information from a DNA turned into a protein?
The information in the DNA is transcribed in the mRNA which is translated into a polypeptide
175
What is said to be the aqueous environment of the cell?
The cytoplasm
176
What are organelles?
- A collection of factories and assembly lines found in the cell
- They have membranes which isolate chemical reactions or ensure that metabolic pathways involving many chemical reactions are efficient
177
What are the different types of organelles?
- Endoplasmic reticulum
- Golgi body
- Mitochondria
- Lysosome
- Vacuole (for cells with cell walls)
178
Where is water stored in cells with cell walls?
In the vacuole
179
What's the function of mitochondria?
They're specialized for the synthesis of ATP
180
What are the functions of endoplasmic reticulum and Golgi?
- They're a protein synthesis and transport system
- They're both connected to the nucleus and to each other
181
What's the purpose of membranes forming microenvironments?
This allows chemical reactions to occur without effecting the rest of the cell
182
What's the cytoskeleton?
- It's composed of specialized rods that grow and shrink
- The plastic organization of the cytoskeleton controls:
- cell shape and cell movement
- transport within cells
- exerts force to move chromosomes or cleave membranes
183
Rods of the cytoskeleton are another example of what?
Polymers
184
How do actin monomers affect the length of microfilaments?
- Actin monomers bound to ATP increase the length of the microfilament
- The energy transferred from ATP to ADP releases the monomer, and the microfilament then shrinks
185
How does tubulin-GTP affect the length of microtubules?
- Tubulin-GTP increases the length of the microtubule (rescue)
- Release of tubulin-GDP causes shrinkage (catastrophe)
186
Where do cilia and flagellum come from?
- They're built from microtubules and motor proteins that use ATP to apply force
- The motor proteins act as little propellers
187
What's a ribosome?
- A huge enzyme composed of many of proteins and RNA molecules
- The ribosome builds a protein by lowering the activation energy for forming a peptide bond
188
What are the 2 microscopes used to study cells?
- An electron microscope (provide very detailed information of dead cells - nanometer resolution)
- A super-resolution light microscope (study live cells with 100s nanometer resolution)
189
What can the GFP found in jellyfish help us with?
Identifying different cells with its fluorescent property
190
Colour variations in a fluorescent protein called GFP were produced through what?
Mutations, protein engineering
191
What are the components of the plasma membrane?
- Phospholipid
- Cholesterol
- Integral proteins
- Peripheral proteins
- Carbohydrates
192
What's the plasma membrane fluid mosaic model?
Lipids + proteins adorned with carbohydrates
193
How do membranes form?
Spontaneously in an aqueous environment
194
What factors determine the rate of diffusion?
- The concentration gradient (steep/shallow concentration)
- The mass of the diffusing molecules (size/shape)
- The temperature of the system (higher temp = higher diffusion
- The density of the solvent (water vs honey)
- Distance travelled (smaller cells allow for more diffusion)
For membranes:
- Solubility, surface area and thickness (1 vs 2 membranes)
195
Describe diffusion across the plasma membrane
- Gases (CO2 & O2) can diffuse across the membrane down across a gradient over time
- They can exchange because they aren’t polar
196
What kind of atoms can't diffuse across the membrane on their own?
Ions (because they're charged)
197
How do cells maintain a charge potential across the membrane that keep the environment suitable?
- They control the number of ions that come in and out of the cell
- This is done through gated channel proteins and carrier channel proteins
- The gated channels sense the concentration and maintain a concentration gradient
- Each carrier protein is specific to one substance, and the rate of transport is therefore limited by the number of carrier channels in the membrane
198
What's osmosis?
- The movement of free water molecules through a semipermeable membrane according to the water's concentration gradient across the membrane, which is inversely proportional to the solutes' concentration
- Water stops crossing the membrane when the concentration of molecules is equal from inside and outside (equilibrium state)
199
What are the 3 different states of tonicity?
- Hypotonic
- Isotonic
- Hypertonic
200
What happens if a saline solution is hypotonic?
Water will go in your cells and they will explode (causing internal haemorrhaging)
201
What happens if a saline solution is hypertonic?
Water will leave your red blood cells and they will shrink
202
Which form of tonicity is best for your cells?
- Isotonic solutions
- Equilibrium between water leaving cell and coming in cell
203
What are some energy exchanges (cellular respiration) that happen between cells and the environment?
- Anaerobic Respiration (Glycolysis) -> cytoplasm and environment
- Aerobic Respiration (Ox Phosphorylation) -> mitochondrion and environment
- Photosynthesis -> Chloroplast with sun and CO2
204
What do you lose with oxidation?
- Electrons from the molecule
- Reduction of potential energy
- In synthesis of ATP there's oxidation
205
What's unique about Hydrogen atoms and their protons, neutrons and electrons?
Hydorgen atoms lack neutrons
206
What do you gain with reduction?
- Electrons
- Gain in potential energy
207
Cells use what to transfer electrons from one molecule to another in a series of coupled reactions?
The electron carrier NAD (Nicotinamide adenine dinucleotide)
208
What's substrate phosphorylation?
- For synthesis of ATP
- The enzyme binds a phosphorylated molecule
(substrate) and ADP), and releases an un-
phosphorylated molecule (product) and ATP
209
What are ATP's 3 phosphate groups?
- Gamma phosphate
- Alpha phosphate
- Beta phosphate
210
By increasing the concentration of hydrogen ions, you can decrease the reaction that forms what?
ATP
211
Glycolysis takes place in the cytoplasm of
what cells?
- Prokaryotic
- Eukaryotic
212
What's the carbohydrate that the cell uses most effectively?
Glucose
213
What's glycolisis?
- Taking glucose, ripping it apart and turning it into 2 molecules
- For this to happen, you need to put energy into the system which is done by using the energy stored in ATP, which will result in one glucose having 2 ATP molecules (pyruvate)
- It's essential for red blood cells because they don't have mitochondria and need glycolysis for ATP synthesis
214
What are similarities between mitochondrion and chloroplast?
- They have similar structures
- They both have specialized, membrane bounded environments that both favour chemical reactions and also keep the reactions coupled so that the synthesis of ATP is efficient
215
What kind of cellular respiration occurs in mitochondria?
Aerobic respiration
216
What happens to pyruvate in mitochondrion?
Pyruvate is transported into the mitochondria, and is oxidized to produce CO2, NADH and Acetyl CoA
217
Which step in the citric acid cycle is most important?
- Step 5
- It produces ATP, GTP and CO2
218
What molecules does the
Oxidative phosphorylation use?
NADH (3)
FADH2 (1)
219
What are the 2 paths that electrons can move through in the electron transport chain?
- Move into the channel and help with chemiosmosis as they enter
- Be passed off to these things diffusing inside the membrane
220
What is proportional to
the number of protons
pumped across the inner
mitochondrial membrane?
The number of ATP
molecules ultimately
obtained by chemiosmosis
221
Where is the electron transport chain located in eukaryotes VS prokaryotes?
- In the inner membrane of mitochondria in eukaryotes
- In the plasma membrane of prokaryotes
222
What's ATP synthase?
It's a large and complex enzyme that catalyzes the synthesis of 90% of ATP
223
Where do H+ ions diffuse through the membrane?
They diffuse (from high to low) through the membrane in the channel (facilitated diffusion)
224
What is the potential energy of glucose used for?
- 34% of the potential energy in each glucose molecule is used for ATP/GTP synthesis
- The remainder is released as heat
225
What are the 2 stages of photosynthesis?
- light dependent reactions
- the Calvin cycle
226
What's the overall function of the light-dependent
reactions in photosynthesis?
- It's to convert solar energy
into chemical energy in the form of NADPH and ATP
- This chemical energy supports the Calvin
cycle reactions and fuels the assembly of sugar molecules (Glucose)
227
What are the inputs from the environment for plants during photosynthesis?
- Water (6 H20)
- 6 CO2
228
What are the outputs from the environment for plants during photosynthesis?
Oxygen (6 O2)
229
How do different wavelengths relate to the energy of photons?
- The longer the wavelength, the less energy the photon carries
- Short, tight waves carry the most energy
230
What initiates the process of photosynthesis?
- Light energy initiates the process of photosynthesis when pigments absorb specific wavelengths of visible light
- Energy levels lower than those represented by red light
are insufficient to raise an orbital electron to an excited
state
- Energy levels higher than those in blue light will physically tear the molecules apart, in a process called bleaching
231
What happens in the photosystems part of photosynthesis?
- In the photosystems, protein complexes and pigment
molecules work together to produce NADPH and ATP
- The reaction centre contains special chlorophyll a molecules that can undergo oxidation upon excitation; they can actually give up an electron
- It's at this step in the reaction
centre during photosynthesis that light energy is converted into an excited electron
232
Describe the process of using CO2 and H2O for photosynthesis
- Oxygen (O2) + ATP + NADH coupled with CO2 will make Sugar + ADP + NAD
- Sugar + ADP + NAD couple with H2O will make Oxygen (O2) + ATP + NADH
233
How bacteria synthesize ATP?
- Bacteria don't have mitochondria or chloroplasts, but use the plasma membrane and cell wall in a similar way to couple reactions needed for ATP synthesis
- Bacteria also generate ATP using glycolysis, pyruvate oxidation and the citric acid cycle, but in the cytoplasm
234
Compare aerobic respiration and photosynthesis
Aerobic respiration vs Photosynthesis:
- Light dependent vs Chlorophyll becomes electron light dependent
- Starts with C6H12O6 vs Ends with C6H12O6
- O2 is a reactant vs O2 is a product
- H2O and CO2 are products vs H2O and CO2 are reactants
235
What are similarities between aerobic respiration and photosynthesis?
- 3-carbon intermediates
- ATP synthase, Hydrogen pumps
- ATP and ADP electron carriers
236
How do things on earth consume CO2?
- Animals and other organisms respire CO2
- Volcanoes emit CO2
- Water, land and plants absorb CO2
237
What happens when fire kills plants?
CO2 increases and O2 decreases
238
What's the relationship between CO2 and temperature?
CO2 traps heat energy from sunlight
239
What would happen if global warming went up a few degrees (ex: 0.5 ºC)?
- It could mean tens of millions more people worldwide exposed to life-threatening heat waves, water shortages and coastal flooding
- Weather will be unpredictable and crops will fail -> have to be genetically engineered
- It could mean no more coral reefs and Arctic summer sea ice
240
What would be an example of a worse case scenario of the greenhouse effect?
- Venus
- Atmosphere dense in CO2 and extremely hot
241
What kind of macromolecule is an enzyme?
A protein
242
What macromolecule contains ATP as a subunit?
nucleic acids or DNA or RNA
