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Karolina [17]
3 years ago
8

When can a cell transport a molecule across the cell membrane without expending energy?

Biology
1 answer:
butalik [34]3 years ago
6 0
When the concentration gradient of such molecules is high on the either the cytoplasmic side or the extracellular side of the cell. When the concentration gradient is high it flows freely through the cell membrane to the other side without expanding energy.

Hope i helped!
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Match the items: a. Heart b. Blood Vessels c. Capillaries d. Lungs e. Kidney 1. Regulates blood volume 2. Can decrease blood pH
Assoli18 [71]
<h2>Answer:</h2>

I believe the correct answer is:

a: 4

b: 3

c: 5

d: 2

e: 1

<h2>Explanation:</h2>

a: Heart - Can increase blood pressure by beating faster

b: Blood vessels - Can lower blood pressure by dilating

c: Capillaries - Exchange oxygen/carbon dioxide with tissues and alveoli

d: Lungs - Can decrease blood pH by increasing respiratory rate

e: Kidney - Regulates blood volume

<h2>Further Explanation:</h2><h3>a: Heart - Can increase blood pressure by beating faster</h3>

The heart is a fist sized organ in the center of the chest cavity and is lying on a wider base that is longer than its height and an apex that elongates to the left side of the chest. It functions to circulate and distribute blood to different regions of the body using blood vessels. The heart has several baroreceptors that sense a decrease in the volume of blood or pressure and it adjusts by beating faster. It also is controlled autonomously by the autonomic nervous system that will also adjust its pace when it recieves signals to do so in the case of low bloo pressure or in cases of high demand such as in a scary activity.

<h3>b: Blood vessels - Can lower blood pressure by dilating</h3>

Blood vessels are hollow tissues that have elastic walls which control the size of its luen. They function to supply blood to tissues in every region of the body. In cases when the blood pressure is too high, it recieves signals from the brain to its muscles that have beta cholinergic receptors that instruct it to dilate/relax so that blood will have inimal resistance hence less pressure as it is passing through it.

<h3>c: Capillaries - Exchange oxygen/carbon dioxide with tissues and alveoli</h3>

These are the smallest of all blood vessels and they are distributed in every region of the body. They have elastic and permeable walls which allow red blood cells carrying oxygen to move into the tissues they are moving through and also nutrients while at the same time they pick up waste and red cells that have collected carbon dioxide from the tissues. They also are densely populated in alveoli to perform the same function during respiration.

<h3>d: Lungs - Can decrease blood pH by increasing respiratory rate</h3>

CO2 is acidic while O2 is a Lewis base. In cases where the blood has a pH that is more basic than the required pH of 7.3, the body either undergoes a metabolic compensation through retaining more bases such as chloride ions. In case there is a problem with the kidney, the body triggers the respiratory system to increase the respiratory rate so that oxygen is not exposed to the alveoli for a longer time to be absored fully hence it will be in blood at a lesser percentage compared to acidic CO2 which will have a higher percentage making the blood more acidic. To understand how these work using a diagram, look at the table below for arterial blood gas.

<h3>e: Kidney - Regulates blood volume</h3>

The kidney filters blood to remove and balance fluids. In the afferent arteriole that supplies the kidney with the blood to be ultrafiltrated there are specific baroreceptrs that sense a rise or a fall in blood volume. The kidney if the volume is low will retain more ions so that it can draw water back into the vasa recta and increasing the blood volume. If the volume is too high, it will lose more ions into urine and so water will be lost as part of urination until the volume stabilizes to the correct volume.

Level: College

5 0
3 years ago
The Sun appears to move from ______________________ to _______________________________across the sky
I am Lyosha [343]

Answer:

East to West

Explanation:

6 0
3 years ago
Give one common characteristic of hardwood trees
ohaa [14]

Hardwood trees have a lot of bark.

(I hope this is good enough.)

3 0
2 years ago
Which of the following best describes ecological succession? A. The change in the genetic makeup of a species over time B. The c
Anarel [89]
I would say D is da best answer not rlly 100 but dats seems da best 2 me  
5 0
2 years ago
An important similarity between photosynthesis and cellular respiration is that both processes
Semenov [28]
Produce energy usable by the cells of their respective organisms. 
8 0
2 years ago
Read 2 more answers
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