Explain the lac operon. How does it work when lactose is present and when lactose is not present. What about the presence of glucose?
Answer: The lac operon is an operon used to transport and metabolize lactose. In the presence of lactose, it functions as an inducer, it binds to the Lac I repressor protein and generate a conformational change that decreases its affinity for the operon region. Thus, the operon region is left free, the RNA polymerase can transcribe the structural genes.
Explanation:
An Operon is a group of structural genes whose expression is regulated by the same control elements and genes. The lac operon is an operon used to transport and metabolize lactose in Escherichia coli bacteria. Lactose is a disaccharide formed by the union of a glucose molecule and a galactose molecule (monomers). Upon breaking the glycosidic bond of lactose, both monomers are released and become available for use for energy. Remember that glucose is the main source of energy, and bacteria will always prefer to metabolize glucose rather than any other sugar, which they will only metabolize as an alternative energy source if glucose is not available.
The operon consists of several structural genes:
Lac z gene: encodes the enzyme β-galactosidase, which catalyzes the hydrolysis of lactose into glucose and galactose.Gene lac y: encodes the protein galactoside permease, for the transport of lactose into the bacterium.Promoter: region of DNA upstream of the above-mentioned genes that controls their expression, and where RNA polymerase binds to carry out gene transcription (synthesis of RNA from DNA that involves the expression of a gene).Operator: region of DNA located between the promoter and the beginning of the structural genes, which is recognized by the repressor protein Lac I.Repressor gene: encodes the Lac I repressor protein, which binds to the operator region and thus prevents transcription of genes under the control of this promoter. When the repressor is removed from the operator (in the presence of inducer which is lactose), RNA polymerase is ready to bind and start transcription.So, the lac operon is under a type of negative regulation, where genes can always be transcribed, except when the Lac I repressor protein is bound to the operator region. The promoter of the lac I gene is constitutive, so the Lac I protein is permanently expressed and remains bound to the operator, preventing the transcription of structural genes. That is, preventing the action of the lac operon in the absence of lactose. However, in the presence of lactose, it functions as an inducer of the operon. It is able to bind to the Lac I repressor protein and generate a conformational change that decreases its affinity for the operon region. Thus, the operon region is left free, the RNA polymerase can freely transcribe the structural genes, the enzyme β-galactosidase is synthesized which can degrade lactose to glucose plus galactose (and thus metabolize the lactose in the medium).
It should be clarified that in reality, the true inducing molecule of the lac operon is allolactose, an isomer of lactose obtained by a transglycosylation occasionally carried out by β-galactosidase. But usually to simplify terms, lactose is referred to as the inducer.
So, the lac operon is always inactive unless there is lactose in the medium. As mentioned, E. coli prefers glucose, so the lac operon will not be activated in the presence of lactose if glucose is present in the medium. If both glucose and lactose are present in the medium, the repressor is inactivated, so the operon is transcribed but at a basal (low) level due to the presence of glucose.
8. Which example describes a consumer?
A. an organism that makes its own food
B. an organism that eats other organisms
C. an organism that breaks down dead material for food
Answer:
your answer is probably gonna be A
Answer:
B. An organism that eats other organisms
Explanation:
which consumers live in neritic zone
Answer:
crabs, shrimp, starfish, scallops and sea urchins
Explanation:
Hellooooooooooooooooooooooooo
Answer:
howwwwwww areeeee youuuuuuuu
A plant can have green (G) or yellow (g) leaves. It can also have a long (K) or
short (k) stem. A scientist is preparing a Punnett square for a dihybrid cross
of a plant with a genotype GGKk. What possible gametes can the plant
produce?
I NEED ANSWERS ASAP!!
How were the governments of Japan and Italy similar in the 1930s? Check all that apply.
Both were headed by groups of military leaders.
Both used extreme nationalism to win support.
Both were supported by citizen armies.
Both began programs of aggressive expansion.
Both were known as militarist governments.
Answer:
The correct answers are:
B. Both used extreme nationalism to win support.
D. Both began programs of aggressive expansion.
The governments of Japan and Italy similar in the 1930s because they both used extreme nationalism to win support and began programs of aggressive expansion.
Explanation:
Both governments (Japan and Italy) used extreme nationalism to win support and both began programs of aggressive expansion.
Similarity between government of Japan and Italy in 1930The governments of Japan with its territory in Asia had a similarity in government with that of government of Italy located in Europe.
In 1930 both governments (Japan and Italy) used extreme nationalism to win support in order to have more allies and they also began programs of aggressive expansion to increase their colonies.
Thus, the correct options include, both used extreme nationalism to win support and both began programs of aggressive expansion.
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1. What is stimulus?
2. Define response.
3. What are tropic movements
4. What excretory products are produced in plants?
5. When do stomata open and close?
Answer:
1.someting that causes directly, development, interest.
2.an answer to somebody something
3.directional movement of particular part of a plant in response to environmental stimuli
4. carbon dioxide, oxygen
5. allow for the uptake of carbon dioxide anf to limit the loss of water due to evaporation
what do you think are some human characteristics that reflect a common ancestry between non human primates and ourselves?
Explanation:
Primates are the mammalian order of organisms, having flexible hands and feet. These organisms have a developed brain and include organisms like lemurs, lorises, humans and apes. Humans are placental mammals, who have a highly developed brain.
Step 2 of 3
The evolutionary relationship between humans and non human primate can be studied based on the anatomical features and behavior that these two organisms share. The human characteristics that reflect a common ancestry between human and non-human primates are as follows:
1. The body hair are present on both the organisms.
2. Giving birth to young ones, after a long gestation period is common in both the organisms.
3. Different types of teeth which are incisor, canine, premolar and molars are present in both the organisms.
4. Both the organisms have the capability to regulate their thermal body temperature.
5. The brain size and capacity of both the organisms is large.
6. The capacity to learn and adapting to suitable behavior based on that is well present in both the organism.
Step 3 of 3
Chimpanzees are primates, belonging to the same ape family as humans. Chimpanzees are the closest living relative of humans. They are basically of two types, pan troglodytes and pan paniscus. Chimpanzee and humans are similar in following ways:
1. Brain volume of humans and chimpanzees is almost similar. Brain volume of human is 1350 ml (milliliter) while that of chimpanzee is 1370 ml.
2. Both humans and chimpanzees socialize among themselves.
3. According to scientific reports, humans and chimpanzees share about 95% similarity in DNA (Deoxyribonucleic acid).
Describing the formation of the Solar system
If Mendel had been working with his pea plants and noticed that not all purple flowers had an equal intensity of purple, what is a likely explanation for the difference?
A. variations in cell signaling driving differences in gene expression
B. variations in the weather
C. variations in how the seed was handled
D. variations in the cell walls
What was one major effect of urbanization on British society during the
Industrial Revolution?
O A. Urban citizens were forced to drink unsanitary and polluted water.
B. Improved living conditions resulted in a decline in the mortality
rate.
O C. Governments passed strict regulations to reduce the levels of
pollution.
D. Wealthy corporations relocated their factories to rural areas.
Answer:
B is the answer
B. Improved living conditions resulted in a decline in the mortality
rate.
Hope it helps
The major effect of urbanization is improved living conditions resulted in a decline in the mortality rate during industrial revolution.
What is industrial revolution?The Industrial Revolution was the shift to new industrial methods in the United Kingdom, continental Europe, and the United States from around 1760 until between 1820 and 1840.
The major effect of urbanization is improved living conditions resulted in a decline in the mortality rate during industrial revolution.
Thus, the correct option is B.
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Watch this video about a river that China is building. Explain how the river will help prevent the negative effects of drought. In your answer, explain any negative effects that you foresee this new river will have on the people or on natural habitats.
Answer: The river will increase Beijing’s water supply, which is currently at risk of not meeting the city’s needs. This increase will help to soften the effect of droughts.
The downside of the new river is that it may disrupt natural areas, including habitats for plants and animals. The project will also be expensive and may take up space that could be used for homes, businesses, or agriculture.
Explanation: Change the wording...
The construction of a new river can help prevent the negative effects of drought by increasing the availability of water for human and ecological needs, and one way that a new river can help prevent the negative effects of drought is by increasing the recharge of groundwater resources.
What is a drought?During periods of drought, water resources can become scarce, leading to reduced crop yields, drinking water shortages, and negative impacts on ecosystems. By providing a new source of water, a new river can help alleviate some of these negative effects. A new river can provide a source of water that can help recharge aquifers and replenish groundwater supplies. However, the construction of a new river can also have negative effects on people and natural habitats. One potential negative impact is the displacement of people living in the area where the river is being constructed. This can lead to the loss of homes, farms, and livelihoods for local communities.
Hence, the construction of a new river can help prevent the negative effects of drought by increasing the availability of water for human and ecological needs.
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Pharmacological management of glaucoma focuses on the reduction of intraocular pressure by increasing the drainage of aqueous humor, decreasing the production, or both. What drug classes are used to reduce intraocular pressure
Answer:
Beta blockers.
Explanation:
Beta blockers are the drugs that blocks the effects of the hormone adrenaline. Beta blockers is responsible for slowing of your heart beat more which ultimately reduce blood pressure. Beta blockers are the drugs which reduce the production of fluid in your eye, thereby lowering the pressure in your eye means intraocular pressure. Examples of beta blocker medicines are timolol (Betimol, Istalol, Timoptic) and betaxolol (Betoptic).
paste or draw pictures of five junk food items and list five harmful effects of those items
What is directly responsible for matter moving and changing in an animal's
body?
A. Water
B. Sun
C. Energy
D. Fuel
Match the structural formula to the chemical formula for this substance.
Hн
но-с-с-он
ІІ.
Hн
C2H2(OH)2
ООО
HOC2OH
С2Н6O2
O H4CO3H2
Answer:
C2H6O2
Explanation:
Just did it on edge...
Answer:
C2H6O2
Explanation:
Edge 2021
Short Answer Questions
What TWO things are necessary for evolution by natural selection to
occur?
4. Which statement is true of all biotic factors?
A. They are alive
B. They are renewable.
C. They use photosynthesis.
D. They use chemosynthesis.
Answer:
option a
Explanation:
Answer:
The answer is A
Explanation:
Biotic factors are living organisms in the ecosystem.Examples are animals,birds,fungi
the answer of what is matter
Answer:
noun
noun: matter; plural noun: matters; noun: the matter
1.
physical substance in general, as distinct from mind and spirit; (in physics) that which occupies space and possesses rest mass, especially as distinct from energy.
"the structure and properties of matter"
a particular substance.
"organic matter"
Similar:
material
substance
stuff
medium
written or printed material.
"reading matter"
2.
a subject or situation under consideration.
"a great deal of work was done on this matter"
Similar:
affair
business
proceeding
situation
circumstance
event
happening
occurrence
incident
episode
occasion
experience
thing
subject
topic
issue
question
point
point at issue
item
case
concern
theme
LAW
something which is to be tried or proved in court; a case.
the present state of affairs.
"we can do nothing to change matters"
3.
the reason for distress or a problem.
"what's the matter?"
Similar:
problem
trouble
difficulty
upset
distress
worry
bother
complication
4.
the substance or content of a text as distinct from its style or form.
Similar:
content
Trust me mark me as brainliest trust me
ONE FOOD CHAIN that was affected by the introduction of wolves and model it
Answer:
Carnivorous
Explanation:
The wolf, also known as the gray wolf or grey wolf, is a large canine native to Eurasia and North America. More than thirty subspecies of Canis lupus have been recognized, and gray wolves, as colloquially understood, comprise non-domestic/feral subspecies.
What would be the reaction of sea anemone if a glass rod touch the tip of its tentacles?
Answer:
releasing venom from the skin
Can someone help me with this please.
What are carbohydrates?
O Water is non-polar which is why other compounds will dissolve in it
O Macromolecules composed of amino acids
O Non-water soluble macromolecules with a high proportion of hydrocarbons
O Macromolecules composed of nucleotides
Answer:
O Non-water soluble macromolecules with a high proportion of hydrocarbons
Explanation:
Carbohydrates are one of the four biological molecules in nature (asides from proteins, nucleic acid, and lipids). Carbohydrates are a complex polymer consisting of several chains of carbon and hydrogen (hydrocarbons).
According to this question, carbohydrates are non-water soluble macromolecules with a high proportion of hydrocarbons.
Without replication, organisms could not successfully
move.
grow and reproduce.
feed.
make proteins.
Answer: grow and reproduce
Explanation:
Give any two examples for each. 1. Floating plants 2. Underwater plants 3. Fixed plants 4. Emergent plants 5. Insectivorous plants 6. Mangroves 7. Desert plants 8. Coniferous trees 9. Deciduous trees 10. Grass 11. Evergreen trees
Answer:
awdwdadadaawdadawdawdadad
Explanation:
awdawdawdadawdawdwaawdawdawdadawdawdwda
A researcher crossed two plants, and informed an assistant researcher to determine the genotypes and phenotypes of the plants that were crossed by analyzing the offspring. The assistant counted 30 plants with green pods and 10 plants with yellow pods. Which of the following conclusions can accurately be made by the assistant?
a. The researcher had selfed a true-breeding plant with green pods.
b. The researcher had crossed true-breeding plants of differing pod colors.
c. The researcher had crossed two heterozygous plants.
d. The researcher had crossed two plants with yellow pods.
e. The researcher had crossed a plant with green pods to a plant with yellow pods.
Answer:
c. The researcher had crossed two heterozygous plants.
Explanation:
Due to technical problems, you will find the complete explanation in the attached files.
Where Adam and Eve really the first people? or where there other people before them, or did adam and eve even exist at all. explain your reasoning.
ᴵ ˡᶦᵏᵉ ᵗᵒ ˢᵉᵉ ʷʰᵃᵗ ᵒᵗʰᵉʳ ᵖᵉᵒᵖˡᵉ ˢᵃʸ ᵃᵇᵒᵘᵗ ᵗʰᶦˢ.
i will give brainly if it is convencing.
Answer:
If you are religious then you might believe in Adam and Eve and the Garden of Eden. But if you believe in science, then you would believe in evolution.
Sapiens or humans have been on the Earth for around 300,000 years.
Earlier ancestors existed 1.4 to 2 millions years ago.
Earliest writing is 5400 years old.
The bible is 2700 years old.
Why was there no record of Adam and Eve earlier?
Because they never really existed until someone created them.
The someone wasn't a deity . It was a man. A man who created a story.
The tissue layers of blood vessels from outer layer to inner layer are:
Answer:
The outermost layer is called the tunica adventitia.
The muscular middle layer is called the tunica media.
The innermost layer is called the tunica intima.
Explanation:
Answer:
tunica intima is the inner most tissue, tunica externa is he outermost layer of a blood vessel
Explanation:
Describe the purpose of pasteurization.
Answer:
Here is some research:
The Purpose of Pasteurization
To increase milk safety for the consumer by destroying disease causing microorganisms (pathogens) that may be present in milk. To increase keeping the quality of milk products by destroying spoilage microorganisms and enzymes that contribute to the reduced quality and shelf life of milk.
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