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Antimicrobial compounds

Antimicrobial compounds

For the following antimicrobial compounds, tell why each inhibits the growth of microogranisms, and why each is selectively toxic (why they are relatively non-toxic for the host)

1) penicillin
2) Steptomyocine
3) Azidothymidine

So I need their mechanism of microbial growth inhibition and basis of selective toxicity.

Cell Biology   chels194   1658   bio_man   13 years ago

Describe two features of the small intestine which help it in the absorption of the products of dige

Describe two features of the small intestine which help it in the absorption of the products of dige

First of all hey, I'm new here. I recently went on yahoo answers and found someone post a link to this site in response to a biology question. I thought i'd check it out. Good site!

I'm a standard grade student in the UK. I'm keen on getting 8 A/1 passes at standard grade.

Ok now that that's over here are my questions.

1. D

General Biology   TheShahMaestro   1490   bio_man   13 years ago

orbitals of electrons in Cl

orbitals of electrons in Cl

Which orbitals are occupied by the electrons of Cl?  What is the shape of each orbital you indicate? 

I will put a few of your posters up on Monday in the biology building at the college. thanks

General Biology   oldcollegelady   1876   2   bio_man   13 years ago

The following shows a restriction endonucleases cleave DNA. abbrev R represents the purines (A&G) ...

The following shows a restriction endonucleases cleave DNA. abbrev R represents the purines (A&G) ...

The following shows a restriction endonucleases cleave DNA. abbrev R represents the purines (A&G) and pyrimidines (C, T & U) are abbrev Y. The abbrev W represents A or T.

Enzyme: PpuMI
Targe Sequence: 5' RGGWCCY 3'
                            3' YCCWGGR 5'

Cell Biology   alatq33   12331   3   bio_man   13 years ago

Hemoglobin Oxygen Binding Curve Question

Hemoglobin Oxygen Binding Curve Question

From the link:

For the following questions, which would it be?

-from A to B
-B to A
-B to C
-C to B

1) the blood pH drops from 7.4 to 7.2
2) The blood CO2 concentration increases
3) THe concentration of 2,3-biphosphoglycerate increases during acclimation to high altitude
4) An infant's fetal hemoglobin (HbF) is rep

Biochemistry   chels194   17521   10   13 years ago

Duddy! Helpenzie me bitta!

Duddy! Helpenzie me bitta!

This time I'm for real about the cookies. 

Let me make sure I understand.  In the examples discussed we assumed that all the genes were heterozygous.  But let’s talk about if some of the genes are homozygous.  I want to see if that will change the way we calculate. 
For example: I think this is a dihybrid cross, AaBb x aabb, so n shoul

12

General Biology   confused_student   7678   18   karim89   13 years ago

In tetrahybridism with 4 independent genes, the F2 produces:

In tetrahybridism with 4 independent genes, the F2 produces:

In tetrahybridism with 4 independent genes, the F2 produces:

a) 81 phenotypes for all pairs of alleles in the dominant condition
b) 16 genotypes for all pairs of alleles in the dominant condition
c) 24 phenotypes for one pair of alleles in the codominant condition
d) 24 phenotypes for two pairs of alleles in the codominant condition

i have the r

Cell Biology   karim89   2481   7   13 years ago

Glycolysis

Glycolysis

So I have this homework assignment and was wondering if I could get some help.

How does oxygen consumption affect glucose metabolism of heart tissue. During an experiment, deoxygenated blood is passed through a heart and measures a constant rate of glucose consumption. Then oxygenated blood is used and glucose consumption drops dramatically, then maintains a steady rate?

Biochemistry   confused   2404   7   karim89   13 years ago

Find the Molality, Millimolality, and Milliosmolality of both Solutions.

Find the Molality, Millimolality, and Milliosmolality of both Solutions.

Suppose a salt and glucose solution are separated by a membrane that is permeable to water but not to solutes. The NaCl solution has a concentration of 1.95g per 250 mL (molecular weight=58.5). The glucose solution has a concentration of 9.0g per 250 mL (molecular weight=180). Calculate the molality, millimolality, and milliosmolality of both solutions. State whether osmosis will oc

Anatomy and Physiology   Kelly185891   11630   2   bio_man   13 years ago

What are two good analogies of the relationship between a non-polar covalent bond, a polar covalent ...

What are two good analogies of the relationship between a non-polar covalent bond, a polar covalent ...

What are two good analogies of the relationship between a non-polar covalent bond, a polar covalent bond and an ionic bond?

 

General Biology   roxana90   4026   bio_man   13 years ago

If they would move spontaneously in one direction, why don’t they quickly come to equilibrium, ...

If they would move spontaneously in one direction, why don’t they quickly come to equilibrium, ...

The cells of your body have Na+-K+-ATPases, which use energy from ATP to pump Na+ out of the cell and K+ into the cell. One result of this is that there is an electrochemical gradient of Na+ ions across the plasma membrane, with more Na+ outside than inside the cell.
-->given this gradient, in which direction will Na+ ions move spontaneously?
-->if they would move sp

General Biology   roxana90   2106   bio_man   13 years ago

The following table outlines the basic steps in the scientific thinking process. Match the biologica

The following table outlines the basic steps in the scientific thinking process. Match the biologica

1.
The following table outlines the basic steps in the scientific thinking process. Match the biological box activity with its corresponding step.
A. OBSERVING
B. FORMING A HYPOTHESIS
C. TESTING THE HYPOTHESIS
D. ANALYZING DATA

__There is a picture of a polar bear on one of the sides of the cube.
__Is the picture on the bottom of the cu

General Biology   vanessa234   1366   star   13 years ago

The cells that line the small intestine can absorb glucose even though the concentration

The cells that line the small intestine can absorb glucose even though the concentration

The cells that line the small intestine can absorb glucose even though the concentration
inside the cell already exceeds the concentration outside of the cell (in the lumen of the
intestine). The protein that transports this glucose into the cell also, at the same time,
brings in a Na+ ion. If this happens, what do you know about the delta-G for the transfer
of N

General Biology   roxana90   1330   sarah!   13 years ago

Drawing a Concept Map help!

Drawing a Concept Map help!

I'm new to concept mapping and my hw question is:

Draw a concept map relating
the structure of water to the following properties:
-hydrogen bonding -polar covalent bonds
-polarity -unequal sharing of electrons
-high specific heat -high heat of vaporization
-less dense as solid -effective solvent
-cohesion -high electronegativity of oxyge

General Biology   roxana90   4796   sarah!   13 years ago

What must be done at the molecular level to make these process be spontaneous?

What must be done at the molecular level to make these process be spontaneous?

In order for a process to be spontaneous it must result
in the release of free energy. But there are many processes that occur within the cells
of your body that absorb free energy. Obvious examples are the contraction of
muscle cells when you lift a book or the absorption of nutrients by the cells
lining your intestine. How is this possible? What must be done at

General Biology   roxana90   1150   sarah!   13 years ago

HELP ON THE PROTEIN ALBUMIN

HELP ON THE PROTEIN ALBUMIN

What (if any) secondary, tertiary, or quaternary?

does it have any special folding?

os it polar or non polar?

thanks!

General Biology   CloGirl1316   2169   5   bio_man   13 years ago

Keratin

Keratin

So I kinda need help w/ this..not really sure about it...

Biochemistry   chels194   2343   9   13 years ago

Glycolysis and pyruvate

Glycolysis and pyruvate

Glycolysis converts glucose to pyruvic acid.
1) List 2 compounds, other than glucose, which are required for this process and why they are required.
2) Then, list 3 compounds, other than pyruvate, which are produced by this process and what is their subsequent use.

Cell Biology   chels194   2147   5   bio_man   13 years ago

Histology

Histology

All tissues consist of two main components:____________ and _____________, which consist of a gelatinous substance called _______ and numerous different _______________.

Please help!! I have read the chapter 2x!!

Anatomy and Physiology   brinkleyracing   1633   bio_man   13 years ago

How do Gatorade drinks rehydrate their user's cells?

How do Gatorade drinks rehydrate their user's cells?

Gatorade & other sports drinks are actually hypotonic solutions. How do these drinks rehydrate their user's cells?

Cell Biology   brinkleyracing   21720   3   lewis   13 years ago

hyperpolarizing graded potential and depolarizing graded potential

hyperpolarizing graded potential and depolarizing graded potential

What happens when a hyperpolarizing graded potential and a depolarizing graded potential of similar magnitude simultaneously arrive at the trigger zone of a neuron?

Anatomy and Physiology   sakura7   4675   2   lewis   13 years ago

two types of sites at a motor end plate

two types of sites at a motor end plate

The acetylcholine released at a neuromuscular junction binds to two types of sites at a motor end plate: receptor sites, and ...

Anatomy and Physiology   7-7   1779   2   lewis   13 years ago

What medical advances over the past 100 years do you think have been the most im

What medical advances over the past 100 years do you think have been the most im

What medical advances over the past 100 years do you think have been the most important? Explain your answer. In your response, include how these advances affect you today. 

General Biology   vanessa234   2788   lewis   13 years ago

Isotonic saline and 5% dextrose in water are solutions that are considered Isotonic to human blood. ...

Isotonic saline and 5% dextrose in water are solutions that are considered Isotonic to human blood. ...

Isotonic saline and 5% dextrose in water are solutions that are considered Isotonic to human blood. What effect on red blood cells would you expect if a patient were given these fluids in an IV? A solution of 10% dextrose in water is hypertonic to blood. What would happen if you were to infuse your pationt with this solution?

Other   brinkleyracing   11949   karim89   13 years ago

Spontaneus

Spontaneus

the cells of your body have Na+-K+-ATPases,
which use energy from ATP to pump Na+ out of the cell and K+ into the cell. One
result of this is that there is an electrochemical gradient of Na+ ions
across the plasma membrane, with more Na+ outside than inside the cell.
-->given this gradient, in which direction will Na+ ions move spontaneously?
-->if

General Biology   gh1991   1117   sarah!   13 years ago

Mitochondrial Cytopathies

Mitochondrial Cytopathies

Which cell populations are the most affected by Mitochondrial Cytopathies?

Anatomy and Physiology   brinkleyracing   27396   3   13 years ago

Drug Diffussion in Blood

Drug Diffussion in Blood

2 Drugs are injected into the same thigh muscle. Drug A is body temp (37 degrees C) and has a molecular weight of 150 g/mol. Drug B has been in the fridge (5 degree C) and has a molecular weight of 600 g/mol. Which drug will diffuse into the blood more rapidly?

Other   brinkleyracing   10094   5   Biology Forums   13 years ago

What sorts of bonds are commonly used in living system to combine atoms into molecules? How does ...

What sorts of bonds are commonly used in living system to combine atoms into molecules? How does ...

What sorts of bonds are commonly used in living system to combine atoms into molecules? How does each form?

High School Level Science   tori022   2134   3   bio_man   13 years ago

Autism Link to Vaccines

Autism Link to Vaccines

Dr. Andrew Wakefield published a paper a dozen years ago, linking vaccination with the development of autism in children. Since then, there has been no reproduction of these findings among the scientific community, and many people have regarded this finding as false. This article was published in The Lancelet, a reputable medical journal. Finally, after 12 years, The Lancelet finall

News Articles and Discussion   john86   1016   Biology Forums   13 years ago

Heart Rate Changes and Homeostasis?

Heart Rate Changes and Homeostasis?

Could someone please explain in detail how and why the heart rate changes during exercise and relaxation to maintain homeostasis?

Specifically, what happens in the body (positive feedback, negative feedback, etc.) and why?

High School Level Science   ysitu   4931   3   bio_man   13 years ago

Deactivating Taste buds.

Deactivating Taste buds.

Which procedure do you think will work better on deactivating the tongue's taste buds temporary? Drying or Numbing with ice? & Why?

Anatomy and Physiology   roflmaolol   1333   sarah!   13 years ago

Dandelion population uncertainty help!?

Dandelion population uncertainty help!?

I need help determinig the uncertainty of the total population. These are my calculations :


Population Density=        average              dandelions/m2
                                   area of hula hoop

Aver

High School Level Science   needbiohelp!   3426   8   13 years ago

Name the chemical test based on a metabolite that can be used to distinguish between these: Pseudomo

Name the chemical test based on a metabolite that can be used to distinguish between these: Pseudomo

Can you guys help me with these questions I cannot find them in my book
Thank you
Name the chemical test based on a metabolite that can be used to distinguish between these:Pseudomonas Vs E. Coli
Salmonella Vs E. Coli
pathogenic Vs Commensal E. Coli
Staphylococcus Aureus Vs S. Epidermis Vs E Coli

Cell Biology   Marin797   2632   3   bio_man   13 years ago

Explain protein secondary structure, tertiary structure, and quaternary structure in terms of these ...

Explain protein secondary structure, tertiary structure, and quaternary structure in terms of these ...

Many of the most important interactions in biology involve non-covalent interactions, such as ionic bonds,
hydrogen bonds, hydrophobic interactions, and van der Waals interactions. Explain protein secondary structure, tertiary structure, and quaternary structure in terms of these non-covalent interactions.

General Biology   roxana90   2889   3   13 years ago

If two single-stranded DNA molecules with complementary sequences are mixed in solution under ...

If two single-stranded DNA molecules with complementary sequences are mixed in solution under ...

If two single-stranded DNA molecules with complementary sequences are mixed
in solution under physiological conditions (as found in a cell), they will base-pair
to form a doubled-stranded molecule. Briefly discuss this process in thermodynamic
terms. Your answer should include the words “spontaneous,” “Gibbs free energy,”
“entropy,” and enthalpy.

General Biology   roxana90   1510   2   13 years ago

Role of non-covalent interactions in the structure of DNA

Role of non-covalent interactions in the structure of DNA

As with proteins, non-covalent interactions play a central role in determining the structure of DNA.
For each type of non-covalent interaction (ionic bonds, hydrogen bonds, hydrophobic interactions, and van der Waals interactions), briefly describe its role in the structure of DNA.

General Biology   roxana90   6984   bio_man   13 years ago

Briefly describe the structure of these molecules and why more energy can be extracted from the...

Briefly describe the structure of these molecules and why more energy can be extracted from the...

Your body stores two types of molecules as energy reserves: glycogen and
triglycerides. Of these two types of molecules, much more energy can be extracted
from triglycerides. Why? Briefly describe the structure of these molecules
and why more energy can be extracted from the oxidation of the fat.

General Biology   croxy7205   6017   2   star   13 years ago

DNA molecules present

DNA molecules present

2. A cell has 8 chromosome in G1 of interphase.
-Draw a picture of this cell with its chromosomes at the following stages (0.5 each).
-Indicate how many DNA molecules are present at each stage (0.5 each).

a. Metaphase of mitosis
b. Anaphase of mitosis
c. Anaphase II of meiosis
d. Prophase I of meiosis

Biochemistry   Princess   1617   4   bio_man   13 years ago

help!!!

help!!!

place the following in order:

Activities during impulse transmittion along a neuron
1. diffusion of ions
2. release of acetylcholine
3. an increase in the permeability of axon membrane
4. an increase in the use of ATP
5. release of cholinesterase
6. conduction of impulse
After the dendiretes of a neuron are stimulated, which sequence of

High School Level Science   BIOLOGY FREAK   910   3   bio_man   13 years ago

Na+-glucose help!

Na+-glucose help!

Na+-glucose facilitated diffusion transporters move sodium ions along with glucose molecules from the outside (extracellular space) of cells to their cytoplasms. During operation of the Na+-glucose facilitated diffusion transporter does the affinity of the transporter for Na+ and/or glucose have to change? Think about whether it is essential that either or both binding sites must ch

Cell Biology   bunton33   1496   3   13 years ago