A car travels a total of 400,000 meters. How many kilometers did the car travel?

(a) Identify the most likely mode of transport across the membrane for substance L. Explain how information provided helps deter

Viefleur [7K]

Active transport occurs against the electrochemical gradient. It needs energy to move molecules from the lower concentration side to the higher concentration side. The mode of transport is active transport. 

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There are three main different types of transport across the membrane

Simple diffusion ⇒ Does not need energy to occur
Facilitated transport ⇒ Does not need energy to occur
Active transport ⇒ Needs energy to occur

Active transport is the transport of molecules that move against the electrochemical gradient, so it does need energy to happen.

Molecules move from the lower concentration side to the higher concentration side of the membrane.

Carrier proteins are in charge of active transport. The needed energy might proceed from the ATP molecules or the membrane's electric potential.

In the exposed example, a scientist wants to determine how substance L enters a cells in a culture.

The cells maintain a 120 mM intracellular concentration of substance L.

Varying external concentrations of substance L (10 to 100 mM) in culture medium (Table 1).

Table 1. Rate of entry of substance L into mammalian cells in culture

External concentration of substance(mM) Rate of entry of substance L

10 5%

20 25%

30 45%

40 65%

50 80%

60 90%

70 95%

80 100%

90 100%

100 100%

Now, we need to identify the most likely mode of transport across the membrane for substance L, and explain how information provided helps determine the most likely mode of transport.

We know that the intracellular concentration is 120mM.

As we can see, this concentration exceeds all of the culture media concentrations. Yet, the substance keep moving into the cell.

As the concentration inside the cell is always higher than the concentration outside, we can assume that this is not passive transport because the molecule transport is going against its concentration gradient.

Hence, the remaining option is active transport. And as said before, we can see it because the substance keeps crossing the membrane toward the cell interior despite its concentration being higher in the interior of the cell than in the exterior.

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6 0

2 years ago

How do endocrine glands differ from other body glands, such as sweat glands?

dusya [7]

Answer: endocrine glands release chemicals into the bloodstream

Explanation: GradPoint

4 0

2 years ago

What would happen if gametes were not haploid?

yKpoI14uk [10]

The offspring would have twice the number of chromosomes it's supposed to have.

6 0

3 years ago

Why are nutrients important to the organism?

Nina [5.8K]

Answer:

Nutrients help break down food to give organisms energy

Explanation:

Nutrients are chemical substances found in every living thing on Earth. They are necessary to the lives of people, plants, animals, and all other organisms. Nutrients help break down food to give organisms energy. The human body can also synthesize some nutrients, such as amino acids.

6 0

3 years ago

Read 2 more answers

In dogs, wire hair is due to a dominant gene (W), smooth hair id due to its recessive allele.a. If a homozygous wire-haired dog

Vsevolod [243]

Answer:

a) All the offspring produced would be a heterozygous in the first generation (F1 generation) with genotype: Ww, Ww, Ww, and Ww. Since wire hair is dominant, all would be wired haired.

b) In the F2 (second generation), we breed the heterozygous offspring from the F1 generation together (Ww x Ww). This will produce 3:1 ratio of dominant:recessive phenotypes having 3/4 of the offspring wire-haired (1/4 WW homozygotes and 1/2 Ww heterozygotes) and 1/4 will be smooth-haired (ww). Also the genotype would have the ratio 1:2:1 (i.e 1 homozygote WW, 2 heterozygote Ww and 1 smooth hair)

c) the chances of producing a smooth-haired pup is 1/4, and the chances of producing a wire-haired pup are 3/4.

d) Therefore, 1/2 of the offspring will have the genotype Ww and be wire-haired, and 1/2 of the offspring will be ww and be smooth-haired. Also the phenotype ratio is 1:1 (1/2 is heterozygote wired hair and 1/2 is smoth haired)

Explanation:

Since the wire hair is the dominant gene (W) and smooth hair (w) is the recessive allele

a) If a homozygous wire-haired dog is mated with a smooth-haired dog, All the offspring produced would be a heterozygous in the first generation (F1 generation) with genotype: Ww, Ww, Ww, and Ww. Since wire hair is dominant, all would be wired haired.

b) In the F2 (second generation), we breed the heterozygous offspring from the F1 generation together (Ww x Ww). This will produce 3:1 ratio of dominant:recessive phenotypes having 3/4 of the offspring wire-haired (1/4 WW homozygotes and 1/2 Ww heterozygotes) and 1/4 will be smooth-haired (ww). Also the genotype would have the ratio 1:2:1 (i.e 1 homozygote WW, 2 heterozygote Ww and 1 smooth hair)

c) If two wire-haired dogs produce a smooth-haired pup, that means that both parents must be heterozygotes (Ww) having a pair of dominant W allele and recessive w allele to pass on to the offspring. Therefore, if these two dogs were to mate again (Ww x Ww), the chances of producing a smooth-haired pup is 1/4, and the chances of producing a wire-haired pup are 3/4.

d) If the mother of the wire-haired male was smooth-haired, that means that the recessive allele w had been passed on to the male making the male a heterozygote (Ww). When this male mates with a smooth-haired female (ww), the cross is Ww x ww. Therefore, 1/2 of the offspring will have the genotype Ww and be wire-haired, and 1/2 of the offspring will be ww and be smooth-haired. Also the phenotype ratio is 1:1 (1/2 is heterozygote wired hair and 1/2 is smoth haired)

8 0

2 years ago