Ch. The Rest Of 6, 7, & 8 Test Flashcards
What is the effect of enzyme concentration on the rate of enzyme action?
Low enzyme concentration= low rate of rxn
Increasing enzyme concentration= increasing rate of rxn
Adding enzyme= no increase rate of rxn
All substrates bind with enzymes
What is the effect of substrate concentration on the rate of enzyme action?
Increasing substrate concentration= increasing rate rxn
Adding more substrate= no increase rate of rxn
Max achieved rate when all enzymes bind with the substrate
What are the two types of enzyme inhibitors?
Competitive inhibitor
Non competitive inhibitor
What is the difference between competitive and noncompetitive inhibitors?
Competitive- binds to active site
Non competitive- does not bind to the active site
What are examples of inhibitors?
Toxins, poisons, pesticides, and antibiotics
What are the two processes involved in regulation of enzyme activity?
Allosteric regulation
Feedback inhibition
How does allosteric regulation work?
Activator stabilizes the active form of the enzyme
Inhibitor stabilizes the inactive form of the enzyme
What does allosteric regulation have?
Allosteric regulated enzymes
What are Allosteric regulated enzymes made from?
Polypeptide subunits
What two forms does Allosteric regulated enzymes have?
Active
Inactive
How does feedback inhibition work?
End product of a metabolic pathway shuts down the pathway
Prevents a cell from wasting chemical resources by synthesizing more product than is needed
What is metabolism?
Totality of an organisms chemical rxns
What are the two types of metabolism?
Anabolism
Catabolism
A—>B—>C—>D
What are the reactants?
What are the intermediate products?
What is the end product?
ABC
BC
D
Each step in a rxn is catabolized by what?
Catalyst
What are the two metabolic pathways?
Catabolic
Anabolic
What is the difference between a catabolic and anabolic pathway?
Catabolic- release energy by breaking down complex molecules into simpler compounds
Anabolic- consume energy to build complex molecules from simpler ones
Why do we eat foods? (Carbs, proteins, fats and lipids)
Sources of substances for biosynthesis of cellular components
Sources of ATP (uses transport of substances, mechanical works, endergonic processes)
What are the end products of the digestion of carbs, proteins, fats and lipids?
Carbs- sugars
Proteins- amino acids
Lipids- fatty acids and glycerol
What is cellular respiration?
Break down of glucose in the presence of oxygen to carbon dioxide and water releasing ATP
Where does cellular respiration occur in a eukaryotic cell?
Mitochondria
Where does cellular respiration occur in prokaryotic cells?
Cytoplasm
Effect of substrate concentration.
Enzyme concentration- limiting (constant)=3
Substrate concentration- variable (x-axis)
Effect of enzyme concentration.
Enzyme concentration- variable (x-axis)
Substrate concentration- limiting (constant)=3
Metabolic pathways.
Series of linked rxns
Begin with a specific reactant and produce an end product
For competitive and noncompetitive inhibitors, does a rxn occur?
No
Another name for rxn?
Catalysis
_____ product feeds back to _____ reactant to make a rxn active again.
Final
Initial
In feedback inhibition the enzyme is the _____.
Final product
Anabolism.
Endergonic (ATP)
Catabolism.
Exergonic ( no ATP, releases ATP)
In cellular respiration, the oxygen in water comes from _____.
The air we breathe
What is the difference between autotrophs and heterotrophs?
Autotrophs- energy from CO2
Heterotrophs- energy form organic compounds
What is the source of energy for autotrophs?
Sunlight
Redox reaction is a reaction that involves transfer of electrons between _____. In _____, a substance loses electrons, or is oxidized. In _____, a substance gains electron, or is reduced.
Reactants
Oxidation
Reduction
C6H12O6 + 6O2 —> 6CO2 + 6 H2O + ATP
what are reactants?
What is reducing agent?
What is oxidizing agent?
What is oxidized?
What is reduced?
Glucose and oxygen
Water
Oxygen
Water
Carbon dioxide
What are the two electron carriers?
NAD and FAD
What is NAD and FADs function?
Electron carriers
Can be reversible oxidized and reduced
What are the oxidized and reduced forms of nicotinamide?
Oxidized: NAD+2H, FAD+2H
Reduced: NADH+H, FADH+H
What are the three types of phosphorylation?
Substrate level
Oxidative
Photo phosphorylation
What is phosphorylation?
Add a phosphate group to ADP to make ATP
Substrate level:
Source of phosphate?
Location in eukaryotes?
Location in prokaryotes?
Organic
Cytosol/matrix
Cytosol
Oxidative level:
Source of phosphate?
Location in eukaryotes?
Location in prokaryotes?
Inorganic Pi
Cristae
Cell membrane
Photophosphorylation:
Source of phosphate?
Location in eukaryotes?
Location in prokaryotes?
Inorganic Pi
Thylakoids in chloroplasts
Thylakoids in cell membrane
Organic compound + ADP —> pyruvate + ATP
What is the donor of phosphate to make ATP from ADP?
Organic compound
In oxidative level of phosphorylation and photophosphoylation, what is the donor of phosphate? What energy is used for oxidative level phosphorylation and what energy is used for photophosphorylation?
Pi
Light energy from the sun
Parts of mitochondria and where are they?
Matrix- inside Cristae
Cristae- wavy
Outer membrane- right outside mitochondria
Intermembrane space- between Cristae and outer membrane
What are the processes used by microbes to generate ATP?
Cellular respiration
Fermentation
What process requires oxygen?
Aerobic
What is the function of oxygen?
Serves as a final electron acceptor
Final electron acceptor of aerobic respiration?
Oxygen
Final electron acceptor of anaerobic respiration?
Anything other than oxygen
Final electron acceptor of fermentation?
Anything other than oxygen
What process generates the most ATP form one molecule of glucose?
Aerobic
What process generates the least ATP from one molecule of glucose?
Fermentation
What are the four stages of cellular respiration of glucose?
Glycolysis
Pyruvate oxidation
Citric acid cycle
Electron transport chain and chemiosmosis
What is another name for glycolysis?
EMP pathway
What part of the cell does glycolysis occur in prokaryotes and eukaryotes?
Both in cytosol
How many steps is glycolysis?
10
What happens during energy investment stage of glycolysis?
2 ATP used?
What happens in conserving in glycolysis?
Makes two private acids
After completion of glycolysis, what happens to glucose?
It is broken down into two molecules of pyruvate
After completion of glycolysis, how many net ATP are produced from on molecule of glucose? By what type of phosphorylation?
2
Substrate level
After completion of glycolysis, how many NADH are produced from one molecule of glucose?
2
What does competitive bind to?
Active site
What does noncompetitive bind to?
Enzyme
What will sugar form to?
CO2
What is NAD derived from?
Niacin
What is FAD derived from?
Riboflavin
What kind of energy do NADH and FADH have?
Potential
What is substrate and oxidative level in?
Animals, plants, bacteria, archaea
What is photophosphoylation in?
Organisms that have chlorophyll
What is Pi?
Inorganic phosphate
What are the types of cellular respiration?
Aerobic and anaerobic
What is the output of glucose?
2 pyruvate + 2 ATP + 2 NADH
What is the total ATP produced in glycolysis?
4
What is the net ATP produced in glycolysis?
2
What is the final product of glycolysis?
Pyruvate
What Happens to pyruvuc acid in pyruvate oxidation?
It is converted to acetyl CoA
How many CO2 are produced from two molecules of pyruvic acid?
2
How many NADH are produced from two molecules of pyruvic acid?
2
What is another name for citric acid cycle?
Krebs cycle, TCA
What part of prokaryotic cell does citric acid cycle occur?
Cytosol
What part of eukaryotic cell does TCA occur?
Matrix of mitochondria
What is the substance that enters the Krebs cycle?
Acetyl CoA
How many steps is the citric acid cycle?
8
After completion of TCA, for two molecules of acetyl CoA, how many ATP are produced and what is the type of phosphorylation?
2
Substrate level
After completion of Krebs cycle, for two molecules of acetyl CoA, how many NADH are produced?
6
After completion of citric acid cycle, for two molecules of acetyl CoA, how many FADH are produced?
2
After completion of TCA, for two molecules of acetyl CoA, how many CO2 are produced?
4
What composes the electron transport system?
4 protein complexes embedded in the membrane
What is the main function of the ETS?
Create a proton motive force (PMF)
What complex in the ETS accepts electrons carried by NADH?
1
What complex in the ETS accepts electrons carried by FADH?
2
As the electrons are passed from one acceptor to another in the ETS, what is released?
Energy
What is the function of the energy that is released as the electrons move down the chain?
Pump protons from the matrix to the intermembrane space
What happens to the H+ concentration outside the membrane and inside the membrane?
Out- more protons
In- less protons
What is the proton motive force?
Proton gradient
What is the final electron acceptor in ETS?
Oxygen
What is chemiosmosis?
The process of ions moving through a membrane from high to low concentration based on concentration and charge
What substance is formed when H+ go back inside the membrane through ATP synthase?
ATP
What is the type of phosphorylation that occurs in the ETS?
Oxidative
In ETS, for one NADH, how many ATPs are formed?
3
In ETS, for one FADH, how many ATPs are formed?
2
Why are there more ATP generated per molecule of NADH than per molecule of FADH?
NADH has more protons than FADH
How many ATP are produced by substrate level phosphorylation?
2
How many ATP are produced by oxidative phosphorylation?
6
Which generates more ATP? Oxidative phosphorylation or substrate level phosphorylation?
Oxidative
How many total ATP are generated?
40
How many net ATP are generated?
38
What stage generates the most NADH?
Oxidative phosphorylation
What enzymes regulate cellular respiration?
Phosphofructokinase, pyruvate dehydrogenase, isocitrate dehydrogenase
Name the inhibitors of phosphofructokinase?
ATP and citrate
Name the activator of phosphofructokinase?
ATP
Name the inhibitor of the pyruvate dehydrogenase?
NADH
What are the two processes that oxidize glucose in the absence of oxygen?
Anaerobic and fermentation
What is anaerobic?
Inorganic molecules as final electron acceptor ( prokaryotes)
What is fermentation?
Inorganic molecules as final electron acceptor
What are methanogens?
Anaerobes, methane producers
What do methanogens do?
reduce CO2 to methane
Where are methanogens found?
Sewage, swamps, marine sediments, and rice patties
What is the carbon source and final electron acceptor of methanogens?
CO2
What are sulfur and sulfate reducing bacteria?
Anaerobes
What do sulfur and sulfate reducing bacteria do?
Produce hydrogen sulfate
What do sulfur and sulfate reducing bacteria do?
Produce hydrogen sulfate
Where do sulfur and sulfate reducing bacteria live?
Mud and organic materials
What are the carbon sources and final electron acceptor of sulfur and sulfate reducing bacteria?
Sulfate
Where does oxidative phosphorylation occur in the mitochondria?
Innermembrane/cristae
High energy electron carriers that donate electrons?
NADH and FADH
What kind of phosphorylation do plants perform?
Photophosphorylation
Does glycolysis require oxygen?
No
What are the two steps of pyruvate oxidation?
Decarbonize
Addition of CoA
Wheee does pyruvate oxidation occur in eukaryote?
Matrix of the mitochondria
Where does pyruvate oxidation occur in prokaryotes?
Cytoplasm
What part of glycolysis has the most production of ATP, NADH, and FADH?
Krebs cycle
Where does ETS happen in eukaryotes?
Cristae/ innermembrane
Where does ETS happen in prokaryotes?
Cell/plasma membrane
What is PMF?
Difference of proton concentration
Flow of electrons
Complex 1 NADH complex 2 FADH—> Q—> COMPLEX 3–> C —>complex 4
1 NADH=
3 ATP
1 FADH=
2 ATP
How many ATP do eukaryotes produce?
36
How many ATP do prokaryotes produced?
38
How many ATP does oxidative phosphorylation produce?
34
How many ATP does standard level phosphorylation produce?
4
What is fermentation?
Anaerobic process generating ATP using organic molecules as final electron acceptors
Two examples of fermentation?
Ethanol fermentation and lactic acid fermentation
Where does ethanol fermentation occur?
Yeast
What does ethanol fermentation produce?
CO2, ethanol, NAD
Where does lactic acid fermentation occur?
In animal cells (especially muscles)
What does lactic acid fermentation produce?
Electrons transferred from NADH to private to produce lactic acid
What is the importance of fermentation?
To get back NAD
Alcoholic fermentation
2CH3CHO + 2NADH —> 2CH3CH2OH + 2NAD
(Acetylaldehyde) (ethanol)
What is reduced?
What is oxidized?
What is oxidizing agent?
What is reducing agent?
Acetylaldehyde
NADH
Acetylaldehyde
NADH
Lactic acid fermentation
2CH3COCOOH + 2NADH —> 2CH3CHOHCOOH + 2NAD
(Pyruvic acid) (lactic acid)
What is reduced?
What is oxidized?
What is oxidizing agent?
What is reducing agent?
Pyruvic acid
NADH
Pyruvic acid
NADH
What causes an oxygen depth to develop?
When the bodies demand for oxygen exceeds the max amount of
Can proteins and fats be used as sources of ATP?
Yes
What are the products of protein digestion?
Amino acids
Amino acids enter what stage of cellular respiration?
Krebs cycle
What are the products of fat digestion?
Glycerol and fatty acids
Glycerol enters what stage of cellular respiration?
Glycolysis
Fatty acids enter what stage of cellular respiration?
TCA cycle
Photosynthesis is a process that converts _____ energy into _____ energy. The energy is stored in the bonds of glucose.
Light
Chemical
Photosynthesis
6CO2 + 6H2O —> C6H12O6 + 6O2
What are reactants?
What is reducing agent?
What is oxidizing agent?
What is oxidized?
What is reduced?
CO2 and H2O
CO2
Water
CO2
Water
What cells in the leaves contain the chloroplasts?
Mesophyll cells
What is stomata?
Epidermal cells
What cells compose the stomata?
Guard cells
What is stoma?
Tiny pore surrounded by guard cells
Why are there more stomata on the underside of the leaf?
To conserve water
What are the parts of a chloroplast? Describe each.
Thylakoid- contains chlorophyll
Granum- stacks of thylakoids
Stroma- space in between
What is the green pigment called in chloroplasts?
Chlorophyll
What do chlorophyll a and b reflect?
Green
Caretenoids: Beta carotene, xanthophyll reflect what colors?
Red, orange, and yellow
What pigment is primarily responsible for photosynthesis?
Chlorophyll a
What are the accessory pigments?
Caretenoids and chlorophyll b
Why are chloroplasts colored green?
Because they absorb every color but green. They reflect green.
What is the stage of aerobic respiration that makes the most CO2?
TCA cycle
What is the purpose of ETS in aerobic respiration?
To create a proton gradient
What is the proton motive force in the mitochondria?
The concentration of protons is higher in the intermembrane than the matrix
Chemiosmosis in the mitochondria is the diffusion of _____ through ATP synthase from _____.
Protons
Intermembrane to matrix
What is the light energy used for photosynthesis?
Sunlight
Visible light is part of the electromagnetic spectrum. What is its color determined by?
Wavelength
What is the relationship between wavelength and amount of energy?
Increasing wavelength=decreasing energy
Inversely proportional to
Photosystems are reaction-center complexes surrounded by ______ and are located in the _____.
Light-harvesting complexes
Thylakoid membrane
What are light-harvesting complexes?
Pigment molecules bound to proteins that funnel the energy of photons to the reaction center
What is a primary electron acceptor?
In the reaction center accepts an excited electron from chlorophyll a
What are the two types of photosystems?
Photosystem 1
Photosystem 2
PS I best absorbs light with what wavelength?
680 nm
PS II best absorbs light with what wavelength?
700 nm
What are the two major stages of photosynthesis?
Light rxns
Dark rxns
What happens with lights rxns?
Photo part
What happens with dark rxns?
Synthesis part
What happens in photo part?
Two photophosphorylation: linear and cyclic
What is synthesis part also called?
Calvin cycle
What rxn is light dependent?
Light rxns
What rxn is light independent?
Dark rxns
Where do light runs take place?
Thylakoids
What are the inputs and outputs of light rxns?
In- H2O, NADP, ADP, Pi
Out- O2, ATP, NADPH
In light rxns, what is solar energy transformed into?
Chemical energy (ATP and NADH)
What are the two pathways of photophosphorylation?
Linear- noncyclic
Non linear- cyclic
Where do dark rxns take place?
Stroma
What are the inputs and outputs of dark rxns?
In- CO2, ATP, NADPH
Out- sugar
What are the photosystems involved in linear phosphorylation?
Photosystems 1 & 2
What photo system functions first?
Photosystem 2
The lost electrons in P680 are replaced by electrons coming from where?
Water
What gas is released when water is hydrolized?
Hydrogen and oxygen
What gas is released when water is hydrolized?
Hydrogen and oxygen
What happens to the electron coming from PS 2?
Replaced by splitting a water molecule
What replaces the lost electrons coming from PS 1?
Transferred to NADP to reduce NADPH
What are the end products of linear phosphorylation?
ATP, NADPH and oxygen
What are the photosystems involved in cyclic phosphorylation?
PS 1
When light strikes PS 1 what happens to the excited electron?
Passed down the ETS
What replaces the lost electron in PS 1?
Electrons that come from the ETS
What are the end products of cyclic photophosphorylation?
ATP
Is water hydrolyzed and O2 released in the process?
Yes
In the light rxn of photosynthesis, 8 photons yield _____ ATP and _____ NADPH.
2
2
The ETS in the chloroplast is in the _____.
Thylakoid membrane
Describe the transport of electrons in the electron transport system in the chloroplast.
Electrons are transported through a series of protein complexes embedded in the thylakoid membranes, moving from photosystem 2 and photosystem 1.
Where does the Calvin cycle take place in the chloroplasts?
Stroma
What does the Calvin cycle produce?
Glucose, NADP, ADP
What are the three steps ( phases) of the Calvin cycle?
Fixation of CO2
Reduction of CO2
Regeneration of CO2 acceptor
What enzyme is involved in step 1?
RuBisCO
What is the substrate of RubisCO?
RuBP
What is the first intermediate product of the Calvin cycle?
12 PGA
What happens in step 2?
12 PGA is reduced by NADPH to form 12 PGAL
How many PGAL are needed to make one molecule of glucose?
2
How many PGAL are reassembled to make 5 molecules of RuBP?
25
How many ATP and NADPH are required to make one molecule of glucose?
8 ATP and 12 NADPH
In the light rxn of photosynthesis, 8 photons yield 3 ATP and 2 NADPH. In the Calvin cycle, 18 ATP and 12 NADPH are required to make one molecule of glucose. How many photons then were absorbed to make one molecule of glucose?
72 photons
Recall the events of the light rxns and the dark rxns.
Light rxns capture light energy to produce ATP and NADPH, which are then used in the dark rxns to fix carbon dioxide into glucose
What are produced in photosynthesis in the chloroplasts that are used for cellular respiration in the mitochondrion?
Glucose and O2
What are produced in cellular respiration in the mitochondrion that are used for photosynthesis in the chloroplasts?
Water and CO2
If the concentration of CO2 in the cell is ______, RubisCO would catalyze the reaction of RuBP with CO2.
High
To conserve water during hot and arid conditions, stomata close. What is the consequence if stomata are closed?
CO2 cannot enter the leaves and oxygen cannot exit.
What is photorespiration?
Alternate pathway for production of G3P by RuBisCO.
If the concentration of CO2 in the cell is _____, RuBisCO would catalyze the reaction of RuBP with oxygen.
Low
Why is photorespiration a wasteful process?
It consumes O2 to make CO2, not making ATP or sugar.
What are the pathways of photosynthesis?
C3
C4
CAM
What kind of cell does the Calvin cycle occur in, in C3 photosynthesis?
Mesophyll
In C3 photosynthesis, the end result of CO2 fixation is what kind of molecule?
G3P (PGA)
In C4 photosynthesis, what type of cell does CO2 fixation by PEP Carboxylase occur in?
Mesophyll
In C4 photosynthesis for CO2 fixation by PEP Carboxylase, what is the enzyme and substrate involved in the initial fixation of CO2?
PEP Carboxylase
In C4 photosynthesis in CO2 fixation by PEP Carboxylase, the four carbon compounds are exported to _____, where they release CO2 that is then used in the Calvin Cycle.
Bundle sheath cells
In C4 photosynthesis in CO2 fixation by RuBisCO (Calvin Cycle), where does it take place?
Bundle sheath cells
CAM plants open their stomata at _____, incorporating CO2 into organic acids. Stomata close during the _____, and CO2 is released from organic acids and used in the Calvin Cycle.
Night
Day
In CO2 fixation in CAM plants, where does it take place?
Mesophyll cells
Does C4 or CAM exhibit spatial separation of steps?
C4
Does C4 or CAM exhibit temporal separation of steps?
CAM
What are the similarities and differences of the three pathways of photosynthesis?
C3: 3 carbon, RuBisCO
C4: 4 carbon, PEP Carboxylase
CAM: 4 carbon, PEP Carboxylase
What pathway is more efficient in hot and dry environments with high light intensity?
CAM
What pathway is more efficient in cool, moist environments with moderate light intensity?
C3
What pathway in more efficient in warm, dry environments with high light intensity?
C4
What is one characteristic that best distinguishes living things from non living things?
The ability to reproduce
What is the continuity of life based on?
Reproduction or cell division
What are the three functions of cell division?
Reproduction
Growth and development
Tissue renewal
What is a chromatin?
A tangled mass of threadlike DNA in a non dividing cell
What is a chromosome?
Condensed DNA molecules observed in dividing cells
How many DNA molecules are there in a single copy chromosome?
1
When the single copy chromosome duplicates, how many chromatids are there?
2
When a single copy chromosome duplicates, what joins the chromatids together?
Centromere
When a single copy chromosome duplicates, how many DNA molecules are there in the double copy chromosome?
2
If the DNA content of the single copy chromosome is x, what is the DNA content of the double copy chromosome?
2 pg, x= 2 chromosomes so 4 chromatids if duplicate, 4 pg
What are kinetochores?
A disc shaped protein structure associated with duplicated chromatids that attach chromosomes to spindle microtubules during cell division
What are kinetochore microtubules?
Protein complexes that attach chromosomes to microtubules of the mitotic spindle
What are somatic cells?
Non reproductive
2 chromosomes (2n, diploid)
What are gamete cells?
Half as many chromosomes as somatic cells (haploid, n)
How many sets of chromosomes are there in a somatic cell?
2
How many sets of chromosomes are there in a gamete cell?
1
What are two types of gametes in humans?
Sperm
Egg
What is the female gamete?
Egg
What is the male gamete?
Sperm
What is the cell cycle?
Orderly set of stages that occur between the time a cell divides and the time the resulting daughter cells divide
What are the two major stages of the cell cycle?
Interphase
Mitotic phase
What are the three stages of interphase?
G1
S
G2
What are the two stages of mitotic phase?
Mitosis
Cytokinesis
How many ATP are made from fermentation from 40?
80
Photosystems work to make ATP and electrons don’t return and are reduced from what?
NADP to NADPH
P680=?
Ps2
RuBisCO at low CO2 _____.
Has a low affinity for CO2
PEP Carboxylase at low CO2 _____.
Has a high affinity for CO2
How many chromosomes does a human somatic cell have?
46
S S
Two single (x)
X X
Two double (2x)
What is the longest stage in the cell cycle?
Interphase
In what stage of interphase are cellular components duplicated except DNA?
G1
In what stage of interphase is DNA doubled?
S
In what stage of interphase do cells prepare for mitosis and double check the duplicated DNA for errors and makes repairs if needed?
G2
In what stage of interphase are centrosomes duplicated?
S
Mitosis
Division of the nucleus
Cytokinesis
Division of the cytoplasm
In mitosis, daughter cells yield _____ number of chromosomes with that of the parent.
Same
What type of cell divides by mitosis?
Somatic
What are the phases of mitosis?
Prophase
Prometaphase
Metaphase
Anaphase
Telephase
Describe the events in prophase.
Chromosomes condense and appear as two sister chromatids
Spindle fiber begins to form
Nuclear envelope breaks down
Centrioles move to opposite poles
Describe the events in prometaphase.
Chromosomes are attached to microtubules
Chromosomes begin to move to center of the cell- congression
Describe the events in metaphase.
Longest phase
Chromosomes line up
Chromosomes attached to opposite poles and are under tension
Describe the events in anaphase.
Shortest phase
Cohesion proteins are cleaved
Sister chromatids separate and move to opposite ends of
Describe the events in telephase.
Two daughter nuclei are formed
Nuclear membranes form, spindle fiber disappears, cytokinesis occurs
Chromosomes become less condensed
Mitosis is complete
Summary of mitosis
P: pair up
M: meet in the middle
A: apart they go
T: two new cells
Describe cytokinesis in animals.
Cleavage furrow
Cell plate inward
Describe cytokinesis in plants.
Cell plate outward
How do prokaryotes reproduce?
Binary fission
Binary fission
Cell splits into two duplicates in first stage
No cleavage furrow, just septum pinching
What are they checkpoints in the cell cycle?
G1
G2
M
G1 and G2 checkpoints are in what stage of the cell cycle?
Interphase
M phase checkpoint is in what stage of the cell cycle?
Metaphase
What are the functions of G1 checkpoint?
Decides if cell should divide
Makes sure cell is large enough to divide
Enough nutrients for daughter cells
What are the functions of the G2 checkpoint?
Makes sure DNA replication in the S phase has been completed
Check to see if DNA is repaired
Triggers start of mitosis
What are the functions of the M checkpoint?
Occurs during metaphase
Checks to see if spindle fibers have formed and attached correctly to chromosomes
What are the two proteins involved in the control of the cell cycle?
Cycling
Cyclin dependent kinases (Cdks)
At what stage in the cell cycle are Cdks activity and cycling concentration high?
G1-S
What will happen if the checkpoints fail?
There will be an over proliferation of _____ which may become _____.
The faulty checkpoints make the cell _____ to check:
Abnormal cells
Cancerous
Unable
If the DNA replication was complete and properly replicated
If mutation in the DNA was repaired
What is cancer?
Unrestrained uncontrolled growth of cells
What can cause cancer?
Failure of cell cycle control
What are the two types of genes that can disturb the cell cycle when they are mutated?
Tumor suppressor
Proto oncogenes
What are pro oncogenes?
Cells that control cell growth, division, and death and when mutated they can lead to cancer
Needed to grow and survive
Describe the functions of p53 protein.
Plays a key role in G1 checkpoint
Monitors integrity of DNA
What happens if p53 protein is mutated?
If DNA is damaged, cell division is stopped and repairs damaged enzymes
If DNA damage is irreparable, p53 tells cell to kill itself
P53 is absent or damaged in many cancerous cells
Transformation
Process in which a normal cell is changed to a cancerous cell
Tumors
Masses of abnormal cells made from cancer cells within normal tissues
Benign
Stays still
Malignant
Spreads/ metastasize
