Ecosystems ____

The count in a bacteria culture was 100 after 20 minutes and 2000 after 40 minutes. Assuming the count grows exponentially, What

Afina-wow [57]

Answer:

Explanation:

Let X be the number of bacteria at time t, and Xo be the initial number of bacteria

Bacteria grows exponentially, the exponential growth model is thus:

X = Xo $e^{kt}$

[e is the exponential sign]

k is the growth constant = growth rate

At t = 20 minutes, X = 100

At t = 40 minutes, X = 2000

Substituting that into the formula

(i) ... 100 = Xo $e^{k20}$

(ii) ... 2000 = Xo $e^{k40}$

Divide (ii) by (i)

$\frac{2000}{100} = \frac{Xoe^{40k} } {Xoe^{20k}}$

20 = $e^{40k-20k} = e^{20k}$

[Xo cancels Xo. Division of values raised to a power is done by subtracting their powers]

Take the natural log of both sides

㏑20 = 20k

[taking the ㏑ cancels the exponential]

k = $\frac{ln20}{20}$

We can now substitute k to solve one of the equations

substituting k in (ii): 2000 = Xo $e\frac{ln 20}{20}.^{40}$

2000 = Xo $e^{0.15*40}$

2000 = Xo $e^{6}$

Making Xo the subject of the formula

Xo = $\frac{2000}{e^{6} }$

Xo is approximately 5 cells.

THE DOUBLING TIME

The doubling time is the time it takes for the population to double, so 5 cells become 10 cells

Since Xo = 5

Given that X = Xo $e^{kt}$

When X=10,

10 = 5 $e^{0.15t}$

solving for t:

$e^{0.15t} = \frac{10}{5}$

Take ln of both sides

0.15t = ln 2

t = $\frac{ln2}{0.15}$

t =4.62 minutes

POPULATION AFTER 65 MINUTES

X = 5 $e^{0.15*65}$

X = 85770

WHEN WILL THE POPULATION REACH 12000

12000 = 5 $e^{0.15t}$

$e^{0.15t}$ =240

take ln of both sides

0.15t = ln 2400

t = 51.89 minutes (approximately 52 minutes)

6 0

3 years ago

Indicate whether each of the following occurs in the ER (E), Cytoplasm (C), Golgi apparatus (G), lysosome (L) or mitochondria (M

Lelechka [254]

Answer:

EELG

(1) Addition of the first GlcNAc oligosaccharides to the asparagine residue of a protein occurs in the Lumen of the Endopslamic Reticulum

(2) Synthesis of phosphatidylcholine occurs in the Endoplasmic Reticulum

(3) Degradation of misfolded ER protein ossurs in the Lysosome

(4) O-linked glycosylation occurs in the Golgiapparatus

Explanation:

1. The covalent attachment of a carbohydrate to a macromolecule such as proteins or lipids is known as glycosylation.

N-linked glycosylation is a very common form of glycosylation and it occurs in eukaryotes in the lumen of the endoplasmic reticulum.

The addition of the first GlcNAc oligosaccharides to the asparagine residue of a proteinmos an example of N-linked glycosylation.

2. Phosphatidylcholine is synthesized through the CDP-choline pathway which occurs at the cytoplasmic face of the endoplasmic reticulum. Choline entering the cell is immediately phosphorylated by choline kinase, converting choline to phosphocholine.

Phosphocholine is then converted to CDP-choline by the second enzyme in the pathway, CTP:phosphocholine cytidylyltransferase (CT).

The phosphocholine moiety is then added to diacylglycerol in a reaction catalyzed by CDP-choline:1,2-diacylgylcerol cholinephosphotransferase to complete the synthesis of phosphocholine.

3. Lysosomes are the cell organelles which are responsible for the breakdown of proteins as well as other components of the cell. Misfolded proteins are identified and transported to lysosomes through chaperone-mediated autophagy, macroautophagy and endocytosis, where they are then degraded.

4. O-linked glycosylation is a form of glycosylation that occurs in eukaryotes in the Golgi apparatus.

4 0

3 years ago

How seeds are an effective adaptation to ensure reproductive success

raketka [301]

They can be spread around to make sure they can grow. Plants reproduce sexually not asexually they can also spread their seeds using insects.

8 0

3 years ago

How Pantene conditioner is used?

Nana76 [90]

Take a tiny bit of conditioner on your palm. Pantene Pro-V Long Black Conditioner is a good product to repair hair damage and giving you long black hair. Step 2 – Apply the conditioner on your hair: Start applying it from your neck's nape all the way to your hair tips, using your fingers to comb it.

7 0

4 years ago

A snickers® candy bar contains 280 calories, of which the fat content accounts for 120 calories. what is the energy of the fat c

Andrei [34K]

5.0 x 10² KJ

From the question given above,

A snickers® candy bar contains 280 calories. Fat content = 120 calories

1 calorie = 4.184 j

120 calories = 120 x 4,184 = 502.08j = 5.0 x 10² KJ

The energy of the fat content is 5.0 x 10² KJ.

6 0

3 years ago

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Ecosystems _____ change.