# Posts by lena

Total # Posts: 1,042

**Evolutionary Science (stem-lineage?)**

I'm reading this article and it says the following: "the PRL regulatory gene HoxA-11 experienced a period of strong positive selection in the stem-lineage of eutharian mammals" What does this mean? I'm not to sure what they mean when they're referring to ...

**Heptic Sinusoid**

Hepatic* and I feel as though they're just areas in which blood pass through. That's all I really know. Is there more to them?

**Heptic Sinusoid**

What's the function of the heptic sinusoid? I've tried googling but I can't seem to find much on it.

**Math**

(4y + 5) /2 = y + 9 - first start off by multiplying both sides by 2 so get rid of the divided by 2 on the left side 4y+5 = 2(y+9) 4y+5=2y+18 - so you want to bring Y's to one side and the numbers to the other 4y-2y= 18-5 2y= 13 y=7.5 Hope this explains it.

**Hydrogen bonding with polypeptides**

Thank you very much.

**Hydrogen bonding with polypeptides**

I'm going to have to ask my prof about this because in lecture she apparently tricked us because we all had chosen C as the answer.

**Hydrogen bonding with polypeptides**

Apparently the correct answer is in fact d) howevere I don't even understand what d) is means. Amide: o=c-nh Aspartyl: CH2-COO- I understand that it may bind to the O- on aspartyl but why would hydrogen binding occur b/t the c-nh when carbon is already bonded to the nitrogen?

**Hydrogen bonding with polypeptides**

In a polypeptide at physiologic pH, hydrogen bonding may form between which of the following? a) side chains of leucine residue and lysine residue b) side chains of aspartyl residue and glutamyl residue c) terminal amino acid group and terminal carboxyl group d) amide group in...

**Peptide Bonds**

Thank you!

**Peptide Bonds**

Which of the following shows linear sequence of atoms joined by covalent bonds in peptide backbone. a) -N-C-C-N-C-C-N b) -N-C-O-N-C-O- c) -N-C-C-O-N-C-C-O d)-N-H-C-C-N-H-C-C The answer is a). Is that because it's the only one that linear; as in it doesn't have any ...

**Chem - Butyrate?**

Where is the butyrate coming form. I now understand the 3-hydroxy aspect of it but how is the end named? Thanks Dr.Bob

**Chem**

CH3-COOH-CH-COO- 3-hydroxybutyrate or β-hydroxybutyrate I have no idea why this is named what it is named. I know that the COO on the end is the most oxidized. I don't understand why a 3 is being used. Would it not be 4 b/c there are 4 carbons. I'm just overall ...

**Chem**

Thanks DrBob!

**Chem**

HCl -> H+ + Cl- In this scenario would the HCl be a strong acid and the Cl- the base? And do you only use the word conjugate bases when dealing with weak acids? Thanks.

**Random question**

Thanks! :D

**Random question**

awesome :O thanks so much ms.sue

**Random question**

Hi this is kind of random but since this is a a homework help website I feel as though you would be able to give me a good answer. I want to be a tutor in my local area for elementary, middle and highschool school kids but I don't really know what to put on my ...

**Biochem - Diabetes**

I drew myself a picture and I think I may understand a little more. This is my new thinking. If you were to just give plain water then the water would be taken up by the cells b/c the solute:water ratio in the cells would be less than that in the blood so water would move from...

**Biochem - Diabetes**

Type 1 diabetic injected insufficient insulin so her body can’t use glucose in blood. Blood glucose is 38 mM (normal value = 3.3-5.8 mM). To adjust osmolality, she increased urine output = dehydration. Should she be treated with water? The answer is NO and my teacher said...

**Calculus**

The area a meadow was approximated by measuring the length of the meadow at 30-foot intervals. THe distances measured across the meadow were 76 ft, 118 ft, 130 ft, 143 ft, 139 ft, 136 ft, 137 ft, 139 ft, 130 ft, 122 ft, and 60 ft. Use Simpson's Rule to approximate the area...

**Math/Radioactive Dating**

I don't think log will work either because I tried it and I got a different answer :(

**Math/Radioactive Dating**

Thanks Reiny :)!

**Math/Radioactive Dating**

Thanks a bunch DrBob! :D

**Math/Radioactive Dating**

I think I know what I did wrong. If someone could let me know if my new understanding is right. If the ratio is 1:3 then you would have 1/4 K and 3/4 Ar so equation should have been: 1/4 = 1/2 ^(t/(1.25 *10^9)) Makes sense? Then as an answer you would get: (log 1/4 / log 1/2...

**Math/Radioactive Dating**

Whats In? I'm so confused :( We were told to figure this out using half-life. Our prof didn't even use logs or anything of that sort.

**Math/Radioactive Dating**

Aha thank you very much! :)

**Math/Radioactive Dating**

My teacher said that if the ratio of mass (in a rock) for 40K and 40Ar was 1:3 then the age of the rock would be 2.5 billion years. I don't understand how he concluded that to be the age. The only thing he knew was that the half-life of K40 = 1.25 billion year. This is my ...

**Math/Radioactive Dating**

How would I calculate the age of a rock only given the amount of each in grams and half-life? 40K decays to 40Ar. Half life of 40K is 1.25 billion years. 40K = 20 grams 40Ar= 5 grams I think the formula is Final Amount of 40K = Initial Amount of 40K * (1/2)^(time/half-life) If...

**Biology**

Supposing you have a renal stenosis, what kind of affect does that have on the heart. What I do know: - decreased flow to the kidneys - kidneys assumes that overall blood volume have decreased - RNN system is activated - = increase in blood pressure (hypertension) I'm ...

**math**

sam has a savings amount that increased in value over a twelve month period from $8765.00 to $9006. he made no deposits or with drawls in that time. What percent interest did he receive for the 12 month period

**5th grade algebra**

thanks ur kind

**calculus ap**

find limit as x goes to infiniti of 8x^4-3x^2+2 over 9x^5+7x^4-3x^2+2

**calculus ap**

what is the slope of the line tangent to the curve y^3+x^2y^2-3x^3=9 at the point (1,2)?

**calculus ap**

thank you

**calculus ap**

what is the slope of a line tangent to y=sin^2(5x+pi) at x=pi/4?

**chemistry**

225

**Chemistry**

How many milliliters of 0.710 M HCl are required to react with 47.80 grams of CaCO3 ? Given the balanced reaction equation: 6 FeCl2(aq) + K2Cr2O7(aq) + 14 HCl(aq) 6 FeCl3(aq) + 2 CrCl3(aq) + 2 KCl(aq) + 7 H2O(l) How many moles of FeCl2(aq) are required to produce 2.811 mol of ...

**Chemistry**

student did the Synthesis of Salicylic Acid experiment using 3.93 g of methyl salicylate. This was the limiting reagent for his experiment. What is the theoretical yield of salicylic acid for his experiment? The theoretical yield is:

**Chemistry**

A student did the Synthesis of Salicylic Acid experiment starting with 3.89 g of methyl salicylate (C8H8O3) and using 40 mL of 6.0 M NaOH. To evaluate her success she needs to determine the limiting reagent. The reaction goes as follows: C8H8O3 + H2O ==> C7H6O3 + CH3OH. ...

**Calculus**

q 0 125 250 375 500 625 750 C'(q) 26 24 30 26 23 25 29 a) If the fixed cost is $8500, use the average of left- and right-hand sums to determine the total cost of producing 500 units. Answer: $ b) How much would the total cost increase if production were increased one unit...

**Calculus**

Match: A. r(1997)−r(1992) B. ∫19921997r′(t)dt C. r(1997) D. ∫19921997r(t)dt E. [ r(1997)−r(1992)/1997−1992] and interpretations: A. Average rate of change of the debt rate between 1992 and 1997 B. Change in debt rate between 1992 and 1997 C...

**Calculus**

Oil is leaking out of a ruptured tanker at a rate of r = 19e^(2t) gallons per hour. Write a definite integral that represents the total quantity of oil which leaks out of the tanker in the first 3 hours. Using your formula answer the following questions: A. Estimate the ...

**algebra**

explain how you could show five less than a number using an expression

**math**

explain who you could show five less than a number using an expression

**math**

how do you write 2320640 in two significant figures?

**Physics**

If I hold a rock at some height and tell you the potential energy there is 25 J, what is it's kinetic energy immediately before it hits the ground?

**geo**

what kind of depositional environment is shale formed in? i think its deep waters but i also need to know about how warm the water is and if its clear or dark ect. I cant find any info on this :(

**Earthquakes**

What determines the magnitude of an earthquake? I know that two plates slide against one another and that creates friction and the potential energy turns into kinetic energy in the form of an earthquake. But how is the magnitude determined? Im thinking the longing the 2 plates...

**geo**

Just to clarify i watch the movie aftershock: earthquake in new york, and i have to state whether i think that the movie was scientifically accurate or not. I said it was not and I said the reason for that were that new york is not on any fault lines. I need 2 more points as ...

**geo**

apparently there are 2 main reasons for an earthquake to occur (correct me if i'm wrong): volcanic activity and plate tectonics. So could I argue that there isnt any volcanic activity in NYC so there wouldnt be earthquakes?

**geo**

I need 3 reasons why a huge earthquake wouldnt occur in NYC. I have the following points: 1) New york city doesn't lay beneath any fault lines I also said that if an earthquake were to occur, the magnitude would be on the lower end of the ritcher scale. But how would it ...

**Biology**

The type of cartilage associated with bone function and development is what? I know that the elastic cartilage contains elastin which allows for elasticity and maintains shape of certain structures. Fibro is strong and rigid (strongest of 3) Hyaline cartilage provides ...

**Bio**

Apparently both fibro and hyaline are responsible but im doing a multiple choice practice test so Im not too sure which it is :l

**Bio**

The type of cartilage associated with bone function and development is what? I know that the elastic cartilage contains elastin which allows for elasticity and maintains shape of certain structures. Fibro is strong and rigid (strongest of 3) Hyaline cartilage provides ...

**Chemistry**

Classify the following reaction using 2 different classifications. 3Sr(OH)2+2Fe(NO3)3=3Sr(NO3)2+2Fe(OH)3

**chemistry**

what features account for carbohydrates high solubility in water?

**math**

a coin is tossed twice and a number cube is rolled. Find probability. 1 head, 1 tail,and 3

**Laptops**

I've been searching a ton of websites but I can't seem to find a proper answer. I'm a first-year Nursing student and I need an opnion on what laptop would best suit me based on my course. Thanks in advance.

**english**

okie dokie :) thanks!

**english**

I still don't get the than and then difference? :S

**english**

why is is "better late than never," rather than "better late then never?"

**infants**

Thanks :)

**infants**

Is there a special name for a baby scale?

**Math-please help!**

Thank you!

**Math-please help!**

the area of the base of a triangular prisim A is 15 square inches and its altitude is 8 inches. Rectangular prism B has a square base that measures 2 inches on each side. If prisim A and prisim B have the same volumes, what must be the altitude of prisim b?

**The Heart**

What is the relationship between fitness level and recovery HR after sub-maximal exercise? I was thinking the more fit you are, the faster your HR will drop back to what it is when you're resting. If you're unfit, it'll take longer for that HR to go down to resting.

**Anatomy (The Heart)**

What is the relationship between fitness level and recovery HR after sub-maximal exercise? I was thinking the more fit you are, the faster your HR will drop back to what it is when you're resting. If you're unfit, it'll take longer for that HR to go down to resting.

**Physics**

The range of human hearing extends from approximately 20 Hz to 20000 Hz. Find the wavelength of these extremes when the speed of sound in air is equal to 343 m/s.

**Science**

why do plastics have to be separated before recycled? Like different kinds of plastics are separated by why? Im on the organic chem unit right now.

**Bio**

Thank you :D

**Bio**

What the technical name for a children ward in the hospital? something like _____netal. im not too sure.

**Digestive System**

thanks!

**Digestive System**

Does the bile duct release bile into the small intestine? And what does bile do?

**Nutrition**

Thanks bobpursley :)

**Nutrition**

Are vegetables comprised primarily of carbs, proteins or fat? I'm talking about the digestive system and I want to know what enzyme breaks down vegetables. Pepsin breaks down proteins which is like meat. Gastric lipase breaks down fats which is like cheese and amylase ...

**Sleep**

Thank you :)

**Sleep**

What would be wrong with someone who can easily sleep up to 20 hours?

**Business**

Which of the following are considered debt investments? Treasury bills Stocks Collectibles Cars

**Business**

Which of the following are considered debt investments? Treasury bills Stocks Collectibles Cars Is it stocks?

**Digestive System**

Pancreatic beta cells release insulin into the blood and INHIBIT the pancreatic alpha cells from secreting glucogon. What does inhibit mean in this context and is the insulin inhibiting or is it the beta cells?

**Rigor Mortis**

When does rigor mortis occur?

**Resume**

Is it essential that you put your address on a resume?

**Business**

Thanks :D

**Business**

Belinda invested a portion of her savings, indicating that the type of investment she made was a loan to a well-known corporation that generates regular fixed interest payments. What did Belinda invest in? I think it's a bond. Am I correct?

**Business**

Christine proudly tells you that she recently got dividends from of one of her investments. She obviously invested in: a) stocks b) GICs c) corporate Bonds d) a money market fund

**science**

"Two children who are fighting over a toy pull on it from opposite sides. The result is a stand-off. Explain this in terms of the net force."

**bio**

is hydrogenated margarine a trans fat? is butter a saturated fat?

**history**

What place did the Israeli Olympic Team visit in the days prior to the hostage taking? I'm thinking it was a memorial of a concentration camp. I'm not too sure.

**algebra**

Solve the following equation: k2 + 4k = 0 By factoring and By using the quadratic formula Can someone please help me to understand how to this problem...I do not understand the steps to get the correct answer. Thanks!!!

**History**

Supposedly there are like 20 major events and i`ve gotten got 3

**History**

What had occurred 40 years prior to the Munich Olympics which made the games so important? The only things I got are the Holocaust, the separation of Israel and Palestine and WW2. Is there anything else that was major?

**History**

True, thank you :)

**History**

Yes, I have read that. But in terms of reconciliation with the Jewish people, that didn't do much, it only caused more problems.

**History**

why were the munich olympic games viewed as being of particular importance world politics, national relations, and reconciliation with the Jewish people? I think the Holocaust occured before that and Germany wanted to prove that they were moving forward and that they werent ...

**careers**

What part of food science does the career of sous chef fall under? Options: preparation, utilization, evaluation,production I was thinking preparation because you're a chef but sous chef also make menus so what would that go under?

**Careers**

Thanks a bunch! :D

**Careers**

How has the job of a sous chef changed over time? I'm not too sure about this. Sous chef has always worked for the head chef and has always done what the head chef has told him/her to do.

**psychology of health**

Has specialized medicine made a positive impact on the quality of patient health care delivery?

**Math-linear programming**

The Furniture Co has two plants. The Eastside one makes Table and Chairs for school classrooms and the Westside one makes Desks and Computer Workstations. (See tables attached in excel). The Furniture Co is considering combining operations of both plants into a single one. ...

**Bio**

I think the word is bioaccumalation