BIO 112 Lecture Notes - Lecture 7: Hydrogen Bond, Boiling Point, Electronegativity

33 views2 pages

lavendergiraffe572

14 Sep 2015

School

University of Rochester

Department

Biology

Course

BIO 112

Professor

Ingrid L.Stefanovic

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Anabolism: synthesis of building basic units to form macromolecules (requires more energy to build things) Metabolism: all the chemical reactions in a cell. Water: has a suitable boiling point and a stable structure. Electronegativity: a measure of the strength of attraction of an atom for electrons. The tendency of an atom to attract electrons towards itself. A high electronegativity indicates a high ability to pull electrons to itself. The differences in electronegativity between oxygen and hydrogen result in a polarized molecules. The partial negative portions of one molecules can interact with the partial positive portions of another molecule. The lifetime of hydrogen bonds in water is 1-2 picoseconds. In solid water, we get four hydrogen bonds and each water molecule forms bonds with 4 other molecules. Hydrogen bonds are relatively weak (23 kj/mol = energy to break a hydrogen bond). Hydrogen bonds are individually weak but together they are very strong.

Related Questions

Which of the following statements about water is not true?

Water will hydrogen bond into highly ordered structures or "cages" around non-polar molecules.

The electron-rich oxygen atom of one water molecule can interact with an electron-poor hydrogen on another water molecule to form a hydrogen bond.

Water is a key player in the energetics of the hydrophobic effect.

In an ice crystal water molecules pack into open lattices consisting of five-membered oxygen rings.

At 25 degrees celsius liquid water is about 85% as hydrogen bonded as the water in ice, with each molecule in an average of 3.4 hydrogen bonds.

Which of the following is the best explanation for the hydrophobic effect?

		It is caused by the attraction of hydrophobic groups for each other.
		It is an entropic effect caused by the tendency of hydrophobic groups to increase their entropy by associating with other hydrophobic groups.
		It is an entropic effect, caused by the tendency of water molecules to increase their entropy by excluding hydrophobic groups, which they must otherwise surround with highly ordered structures.
		It is caused by the attraction of water for hydrophobic groups.
		It is an entropic effect, caused by the tendency of water molecules to increase their entropy by forming highly ordered structures around the hydrophobic groups.

The type of macromolecule found in highest concentration on a weight basis in a HeLa cell is

protein.

lipid.

polysaccharide.

nucleic acid.

water

Co and Zn ions are required by humans in

microgram amounts.

gram or near gram amounts.

kilogram amounts.

d. milligram amounts.

Which description best characterizes the length of a hydrogen bond between water molecules?

About the same length as the calculated van der Waals distance for two water molecules.

About the same length as a covalent O----H bond.

Shorter than a covalent O---H bond.

Longer than a covalent O---H bond, but shorter than the calculated van der Waals distance between water molecules.

Which of the following statements about water is not true?

Water will hydrogen bond into highly ordered structures or "cages" around non-polar molecules.

The electron-rich oxygen atom of one water molecule can interact with an electron-poor hydrogen on another water molecule to form a hydrogen bond.

Water is a key player in the energetics of the hydrophobic effect.

In an ice crystal water molecules pack into open lattices consisting of five-membered oxygen rings.

At 25 degrees celsius liquid water is about 85% as hydrogen bonded as the water in ice, with each molecule in an average of 3.4 hydrogen bonds.

Which of the following is the strongest?

Ionic interactions

Permanent dipole - permanent dipole interactions

London dispersion forces

Co-linear hydrogen bonds

Which of the following is the best explanation for the hydrophobic effect?

It is caused by the attraction of hydrophobic groups for each other.

It is an entropic effect caused by the tendency of hydrophobic groups to increase their entropy by associating with other hydrophobic groups.

It is an entropic effect, caused by the tendency of water molecules to increase their entropy by excluding hydrophobic groups, which they must otherwise surround with highly ordered structures.

It is caused by the attraction of water for hydrophobic groups.

It is an entropic effect, caused by the tendency of water molecules to increase their entropy by forming highly ordered structures around the hydrophobic groups.

Which of the following is NOT defined as a buffer? (pKa PIPES-H⁺ = 6.76; pKa MOPS-H⁺ = 7.15; pKa HEPES-H⁺ = 7.47)

0.15 M MOPS, pH 6.50

0.05 M HEPES-H⁺ / 0.04 M HEPES

0.20 M PIPES, pH 7.97

0.01 M HEPES, pH 7.30

Why does an electron have lower potential energy in an H-O bondthan in an O=O bond?

H has a higher electronegativity than O.

O=O is not stable.

O=O contains a double bond.

The electrons are closer to the oxygen atom in the H-O bond.

None of the answers are correct.

How is the energy from the electron transport chain used mostdirectly?

to form the bonds of a water molecule

to pump hydrogen ions across the mitochondrial inner membraneinto the mitochondrial intermembrane space

to join ADP with a phosphate

to decompose glucose into pyruvate

to rotate ATP synthase

Which process provides the energy needed to pump protons acrossthe mitochondrial membrane during oxidative phosphorylation?

the transfer of electrons in redox reactions

the breakdown of ATP to ADP

the rotation of the ATP synthase rotor

oxidation of isocitrate

None of the answers are correct.

What causes the ATP synthase rotor to spin?

the passing of electrons through ATP synthase

the movement of protons across the mitochondrial membrane

the movement of electrons across the mitochondrial membrane

the synthesis of ATP from ADP and a phosphate group

None of the answers are correct.

What of the following generates the proton-motive force duringoxidative phosphorylation?

buildup of NADH molecules at protein complex I

movement of H⁺ ions across the mitochondrial membraneduring electron transport

rotation of the ATP synthase rotor

joining of H⁺ ions with oxygen to form water

None of the answers are correct.

Suppose a microorganism invades a cell, causing damage to ATPsynthase. How would cellular respiration be affected?

Electrons could not be passed down the electron transportchain.

ADP could not be joined with a phosphate to form ATP.

Hydrogen ions could not be pumped into the mitochondrialintermembrane space.

The cell could not release any energy from the glucosemolecule.

Glucose could not be broken down into pyruvate.

Which molecules transport electrons from the citric acid cycleto the electron transport chain?

NADH and FADH₂

ATP and ADP

GTP and GDP

oxaloacetate and citric acid

None of the answers are correct.

Which type of reactions control the energy release from glucoseduring the citric acid cycle?

acid-base reactions

redox reactions

random reactions

All answers are correct.

None of the answers are correct.

What is the role of NAD⁺ in cellular respiration?

to receive electrons from the citric acid cycle and deliver themto the electron transport chain

to catalyze the synthesis of ATP from ADP

to accumulate in the mitochondrial intermembrane space tofacilitate ATP synthesis

to serve as a substrate to bind to acetyl-CoA at the beginningof the citric acid cycle

None of the answers are correct.

10.

Which molecule enters the citric acid cycle?

glucose

pyruvate

ATP

acetyl-CoA

None of the answers are correct.

apricotgoose897

BIO 112 Lecture Notes - Lecture 7: Hydrogen Bond, Boiling Point, Electronegativity

Document Summary

Get access

Related textbook solutions

Molecular Cell Biology

Biology: Science for Life with Physiology

Concepts of Biology

Biology

Essentials of Biology

Related Documents

BIO 110 Lecture Notes - Lecture 2: Polysaccharide

BIOL-L 112 Lecture Notes - Lecture 1: Alkalosis, Emergence, Olive Oil

BIOL 2051 Lecture Notes - Lecture 2: Covalent Bond, Ionic Bonding, Chemical Polarity

Related Questions