Answer: At low temperatures the fluidity of the membrane decreases and it favors fluidity. The higher the concentration of unsaturated fatty acids, the less tightly the phospholipids can bind and the more fluid (more permeable).
Explanation:
The plasma membrane is a lipid layer that delimits the entire cell, dividing the extracellular medium from the intracellular (the cytoplasm of a cell). They are composed of phospholipids, which are molecules composed of glycerol, a phosphate group and two lipid chains (such as fatty acids). Glycerol is a three-carbon molecule that functions as the backbone of this membrane. A geometry is formed that allows the phospholipids to line up side by side to form broad sheets. They are insoluble in water, but their unique geometry causes them to aggregate in layers without any energy input, as they possess a hydrophilic phosphate head and a hydrophobic tail consisting of the two fatty acid chains. The hydrophilic heads of the phospholipids in a bilayer membrane face outward and are in contact with the aqueous fluid inside and outside the cell. Because water is a polar molecule, it readily forms electrostatic (charge-based) interactions with the phospholipid heads.
Selective permeability is a property of the plasma membrane and other semipermeable membranes that allow only certain particles to pass through them. In this way, those particles that are needed by the cell can enter the cell and those that are not useful to the cell are prevented from entering. In the same way, the cell can eliminate the particles it has produced as waste. In this way, the entry and exit of substances through the membrane is regulated and the correct functioning of the cell is achieved.
For a particle to be able to cross the plasma membrane it must have a size equal to or smaller than the pores of the membrane, it must have the opposite charge to the charge of the membrane or simply have a neutral charge, and if it is larger than the pores it must be dissolved in a solution, decreasing its size and thus be able to enter the cell through the membrane.
Plasma membranes are fluid and this fluidity depends on their lipid composition and temperature. Depending on the temperature, membrane lipids can be found in two different states or phases: gel (solid-like, with more rigid hydrocarbon chains) and liquid crystal (more fluid, with more mobile hydrocarbon chains). At low temperatures the fluidity of the membrane decreases and in these conditions the increase of its concentration favors fluidity. The temperature at which the transition from one state to the other occurs is the phase transition temperature (Tc). At values below Tc, the bilayer is in the gel state and at higher values it passes to the liquid crystal. It should be noted that there is an equilibrium between the gel state and the liquid crystal state and that the characteristics of the lipids of the bilayer condition the transition temperature. In the case of bilayers consisting of only one type of lipid, the Tc is well defined. But biological membranes are complex lipid mixtures and the transition from one state to another occurs over a range of temperatures. The presence of short-chain or unsaturated fatty acids reduces the transition temperature, while saturated fatty acids and the increase in the length of the hydrocarbon chains cause this temperature to rise. Then, phospholipids with unsaturated fatty acid tails cannot bind as tightly due to the bent structure of their tails. For this reason, a membrane of unsaturated phospholipids remains fluid at lower temperatures than a membrane of saturated phospholipids.
The fluidity of a membrane is the ability of a molecule to move through it. In short, the higher the concentration of unsaturated fatty acids, the less tightly the phospholipids can bind and the more fluid (more permeable) the membrane will be even at low temperatures. However, at low temperatures the fluidity of the membrane decreases (lower permeability) but the effect will depend on the composition of the fatty acids. To determine the exact permeability, it is necessary to relate the concentration of unsaturated bonds and the length of the fatty acids in the phospholipids and the temperature.
Explain why your model improves upon the student’s original model. How would your model help someone who was learning about photosynthesis for the first time? Plato question
Answer:
Due to inclusion of more steps of photosynthesis.
Explanation:
My model is more advance than the student's original model which provides more information about the process of photosynthesis to the learners by explaining various parts of photosynthesis. My model presents the various steps of photosynthesis in a very efficient way with the help of including some extra parts. The student's original model is not more advance so it can't provides more information about the process of photosynthesis so that's why my model provides more information about photosynthesis.
Answer:
This model shows all the major molecules involved in the Calvin cycle and how they change at each stage of the process. This added detail would clarify that the Calvin cycle is a series of complex steps. The student’s original model didn’t show this breakdown at all, and it shows only the final products. This model also shows the number of each molecule created, which the original model doesn’t do.
Laying the groundwork for the 'germ theory' of disease _________ discovered that organisms cannot spontaneously arise, but must be introduced into an environment.
A. Anthony Van Leeuwenhoek
B. Louis Pasteur
C. Robert Hooke
D. Ernst Ruska
Laying the groundwork for the 'germ theory of disease, Louis Pasteur discovered that organisms cannot spontaneously arise, but must be introduced into an environment.
Who was Louis Pasteur?Louis Pasteur was a chemist and microbiologist. He is known for the discovery of vaccines, fermentation, and pasteurization.
The germ theory is given by Pasteur. He first of all states that process fermentation is done by living organisms, bacteria, and yeast.
Thus, option B. Louis Pasteur is correct.
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3. What is the change in a population's allelic frequency due to chance?
natural selection
gene pool
genetic drift
allelic frequency
Answer:
option c is the answer to this question
genetic drift is the answer
help with this question 20pts
6 (A)=(x)sebaceous gland
What kind of rock is this?
igneous
Where would this rock most likely be formed?
To which group of rocks would this rock belong?
Rocks can be classified based on texture. The
size of the grains in a rock affects its texture.
Coarse-grained rocks have large grains, and fine-
grained rocks have small grains.
Rocks formed from magma under Earth's surface
have larger grains than rocks formed from lava
on Earth's surface. This is because magma cools
slower underneath the ground than it does above
ground.
Metamorphic Rock Isua
Metamorphic rock, estimated to be as old as 3.8 billion years, located near Isua at Qorqut Sound, Greenland.
Answer:
What kind of rock is this?
✔ igneous
Where would this rock most likely be formed?
✔ underneath Earth’s surface
To which group of rocks would this rock belong?
✔ coarse-grained rocks
Explanation:
Just worked on this assignment
I need help which one is it so I can pass summer school
Answer:
the correct answer is will be option b
Explanation:
I hope this help you have a great day
Which of these organelles is NOT in animal cells?
Ribosome
Endoplasmic Reticulum
Cell Wall
Many animals have a mutually-beneficial, symbiotic relationship with bacteria that reside in their guts. To study the effects of these relationships in more detail, research organisms such as fish and mice have been raised under germ-free conditions. What important process do you predict is compromised in germ-free mice
Answer:
Explanation:
Quá trình tiêu hoá và hấp thụ chất dinh dưỡng
What's the common ecosystem of a Paramecium aurelia
Answer:
Paramecium live in aquatic environments, usually in stagnant, warm water. The species Paramecium bursaria forms symbiotic relationships with green algae. The algae live in its cytoplasm. Algal photosynthesis provides a food source for Paramecium.
In a separate maddyase experiment using (Et)-10nM, the reaction velocity is measured as 3uMS. What is the substrate concentration used in the experiment
Answer: hello your question has some missing data attached below is the missing data
Applying the Michaelis-Menten Equation
An enzyme is found that catalyzes the reaction X ⇋ Y Researchers find that kcat for this enzyme is 600s^-1 and carry out several additional experiments.
answer :
substrate concentration [ x ] = 10⁻⁵ M
Explanation:
Given data:
[Et ] = 10 * 10⁻⁹ M ,
Reaction velocity ( V₀ ) = 3* 10⁻⁶ Ms⁻¹
applying Michaelis-Menten Equation
= 3* 10⁻⁶ = [tex]\frac{600 *10*10^{-9} * (X) }{10^{-5} + (X) }[/tex] ,
= ( 3 * 10⁻⁶ )( x ) + ( 3 * 10⁻¹¹ ) = ( 6 * 10⁻⁶ ) ( x )
hence the substrate concentration [ x ] = 10⁻⁵ M
answer f and g urgently
it relates to the picture
Validity of an experiment is based upon:
Answer:
it is based upon the correlation between the results of your measurements and the results of the criterion measurement.
I hope this helps
Which group evolved first?
rays
skates
sharks
chimaeras
Answer:
C - Sharks; (took the test)
Explanation:
Sharks evolved nearly 420 million years ago. Chimeras, skates, and rays are all related to sharks through their ancestry.
Answer:
I hope this helps.
Explanation:
Which statements describe the synapse? Select all that apply.
It carries information through electrical impulses to the cell body.
It is part of the neuron.
It ensures that information travels in one direction only.
It carries information through chemical impulses to the cell body.
It is the gap between neurons.
It ensures that information travels in multiple directions.
Answer:
A
Synapse, also called neuronal junction, its carries of information through electric nerve impulses between two nerve cells (neuron) or between a neuron and a gland or muscle cell (effector).
Answer:
A
C
E
Explanation:
I just took the quiz on edge
Using complete sentences, explain how proximity to major rivers influenced the location of early cities.
Answer:
Locations along rivers meant faster travel upstream and downstream to rule territories. The city became the place where the ruler or rulers lived together in a stationary spot. The city's location along early rivers encouraged stronger government, which in turn encouraged stronger cities.
Rivers are one of the most crucial resources that played a major role in the development in ancient times. It led to river valley civilization that influenced the location and kingdoms.
What is river valley civilization?The river valley civilization was one of the most important events that led to the establishment of many kingdoms and regions. The proximity to the river banks influenced many factors.
The cities located on the riverbanks have greater development in services including import, export, travel, agriculture, accessibility, etc. This allowed the people to practice agriculture on a large scale due to the availability of the irrigation system.
The river banks allowed the cities to grow as major trade centers and allowed downstream and upstream travel easier. This also led to the emergence of strong government systems.
Therefore, the proximity to major rivers led to river valley civilization.
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PLS HELP
what reproductive process do bacteria use by forming two identical cells from one parent cell?
a. binary fission
b. fragmentation
c. vegetative propagation
d. fertilization
pls answer quick , i have a time limit and i need help
Answer:
A. Binary Fission
Explanation:
During binary fission, the chromosome copies itself, then it forms two genetically identical copies.
As compared to the circulatory system of most fishes, the circulatory system of adult amphibians has the advantage of a single circuit. partially-separate circuits for gas exchange and systemic delivery of blood. complete separation between oxygenated and deoxygenated blood. a four-chambered heart. a pocket of the gut that serves as an air bladder.
Answer:
Partially separate circuits for gas exchange and systemic delivery of blood.
Explanation:
Adult amphibians have separate circuits for gas exchange and systemic delivery of blood. Fishes usually breathe through gills and very few have nostrils. The fishes can breathe underwater with the help of their gills.
Explain briefly four
why, peasant
farmers find it diffcult to get
farm credit
Answer:
The peasant farmers operate mainly in the rural environment of the country. They operate on very small holdings using mostly traditional method because, their income is relatively low and the capacity to save is poor. Therefore needs for credit in order to meet the small farmers output and input
Biology MCQs please help
(1) Group of cell that work together as one to perform a single function is termed as Tissue . Then the group of tissue combine to form organs and further they combine to organ systems and further they combine to form organ system .
(2) They are unicellular green algae which belongs to family Volvocaceae of the Plantae Kingdom
(3) Hypothesis is the assumption which are taken on the behalf of the observation on small scale . They can be correct or incorrect depends on the number of observation and Hypothesis.
(4) Viruses are included in any of the kingdom because they are on the intermediate line of living and non living as they show properties of non living outside the host and properties of living inside the host
Which of the following structures contain the highest conc of RNA..
A) Centriole B) Lysosome
C) Chromosome D) Nucleolus
Answer:
D.) Nucleus
Explanation:
The Nucleus structure contains the highest conc of RNA..
Hope it is helpful to you ☆
Which of the following is not true of integrin? Question 4 options: Integrin molecules serve as stable, permanent anchors that anchor a cell to the extracellular matrix. Integrins undergo extensive conformational changes on binding to molecules on either side of the plasma membrane. Certain intracellular chemical signals can activate integrins from inside the cell, causing them to reach out and grab hold of extracellular structures. When integrin binds to the extracellular matrix, it stretches into an extended, activated state to attach to molecules on the inside of the cell.
Answer:
Integrin molecules serve as stable, permanent anchors that anchor a cell to the extracellular matrix.
Explanation:
Integrins are transmembrane protein receptors that attach the cell cytoskeleton to the extracellular matrix (ECM) in animal cells. These glycoproteins (integrins) are highly dynamic heterodimeric molecules that anchor cells in their position and transduce signals into and out of cells. Integrin-ligand binding activates signaling pathways that are involved in fundamental cellular functions including, among others, organization of the cell cytoskeleton, cell migration, regulation of the cell cycle, etc.
The statement i.e. not true is Integrin molecules serve as stable, permanent anchors that anchor a cell to the extracellular matrix.
The following information should be considered:
Integrins are considered to be the transmembrane protein receptors that attach the cell cytoskeleton to the extracellular matrix (ECM) in animal cells. These glycoproteins (integrins) are highly dynamic heterodimeric molecules that anchor cells in their position and transduce signals into and out of cells.Integrin-ligand binding activates signaling pathways that are involved in fundamental cellular functions including, among others, organization of the cell cytoskeleton, cell migration, regulation of the cell cycle, etc.Learn more: brainly.com/question/16911495
Traits can also be
, which means they can be masked
Answer:
is that a question?
Explanation:
The corpus callosum separates the brain into two halves. separates the brain into two halves. is a large network of neurons on the cerebral cortex. is a large network of neurons on the cerebral cortex. is a thick band of neural fibers enabling communication between the two brain hemispheres. is a thick band of neural fibers enabling communication between the two brain hemispheres. describes the hemispheres of the brain
Answer:
is a thick band of neural fibers enabling communication between the two brain hemispheres.
Explanation:
A brain can be defined as an organ of soft nerve tissue that is found in the skull of vertebrates and it's typically responsible for the coordination of nervous activities, intellect and sensation.
The human brain consists of various sections and these includes;
I. Anterior Cingulate Cortex (ACC) which resembles a bow or collar surrounding the frontal part of the corpus callosum. This is the frontal part of the cingulate cortex which helps to make complex cognitive functions such as impulse control, decision-making, emotions and empathy.
II. Ventral prefrontal cortex in humans are interconnected with the brain and are responsible for the processing of risk, empathy, fear and social decision-making
III. The Cerebral Cortex: this part of the brain primarily comprises of grey matter, foldable sheets of neurons and forms its outermost layer. Therefore, cerebral cortex is known as the outermost layer of the brain (cerebrum) and thus, makes up half of its weight. It is about 2.5 millimeters in thickness and as such it's able to fold.
The corpus callosum is a large, thick band of C-shaped neural fibers found beneath the cerebral cortex and it's saddled with the responsibility of enabling communication between the two brain hemispheres i.e the right hemisphere and the left hemisphere.
What part of the membrane do you think would allow the red tip of the tube worm to send signals to the rest of its body?
Answer:
neurons
Explanation:
I was reading an article and that was the only thing that really stood out...
Osteoporosis is a disease that affects the bones and leads to an increase in bone fractures. Osteoporosis is most likely
to be affected by which cycle?
Answer:
osteoporosis is most likely to be affected by phosphorus.
I hope this helps
In paragraph form (automatic 1-pt deduction if not), explain the evolutionary benefits of sexual reproduction as a means of increasing variation. Be sure to include (a) at least two ways in which sexual reproduction impacts genotype (i.e. genetic effects), and (b) two ways in which sexual reproduction may affect phenotype (i.e. trait effects).
Answer:
See explanation
Explanation:
According to the theory of evolution,species which are better adapted to their environment tend to survive and reproduce in a population passing on these favourable characteristics to their offsprings.
During sexual reproduction, genes can be arranged in new ways from chromosomal crossing over and recombination. This introduces new gene combinations(genotype) and ultimately variation in the population.
This variation may also lead to the observation of new phenotypes in the population.
A lion chases an antelope, which narrowly escapes being eaten. Which
energy conversion saved the antelope's life?
Answer:
Chemical energy to kinetic energy.
Explanation:
Answer:
Chemical energy
Explanation:
i think this is your answer for your question i think maybe its correct if its correct pls tell ok
Question 1 of 25
The overall increase in the amount of carbon dioxide in the atmosphere
directly corresponds with all of the following except.
A. the decrease in the growth rate of some human populations.
B. changing weather patterns.
C. the overall increase in average global temperatures.
O D. the melting of the ice caps.
Two populations of frog species are separated by a group of mountains. A tunnel is built through the mountains, through which some of the frogs are able to safely navigate, and attempt mating with frogs on the other side of the tunnel. However, their heroic feat is for nothing, because their offspring all produce sterile young. This scenario is an example of
Answer:
Post reproductive isolation → Hybrid sterility
Explanation:
The biological concept of species states that individuals of a species can not mate and reproduce with individuals of another species. But if they get to reproduce, the progeny will not be viable or fertile. There will not be any reproductive success.
There are different reproductive isolation mechanisms, which are barriers that inhibit or interrupt the genetic flow between different species.
Reproductive barriers are isolation mechanisms that prevent mating between two or more species. The prezygotic mechanism avoids fertilization between individuals of different species, while the postzygotic mechanism impedes the zygote to develop and reach the adult stage.
Postzygotic mechanisms or barriers include
Hybrid inviability, Hybrid sterility, Hybrid decreased viability or fertility, Cytoplasmic interactions.In the exposed example, it seems that the mountains separating the frogs´ populations made a place for the development of postzygotic barriers, specifically hybrid sterility. Frogs from one population get to mate and produce offspring with the frogs of the other population, but their progeny is sterile.
y’all i need help please help
Answer: It is (D) Skin
Explanation: Skin can absorb materials, it also protects our body, it also regulates our body temp.
