Cell Bio Ch 2

Subunit -

A monomer that forms part of a larger molecule, such as an amino acid residue in a protein or a nucleotide residue in a nucleic acid. Can also refer to a complete molecule that forms part of a larger molecule. Many proteins, for example, are composed of multiple polypeptide chains, each of which is called a protein subunit.

Sugar -

A substance made of carbon, hydrogen, and oxygen with the general formula (CH2O)n. A carbohydrate or saccharide. The "sugar" of everyday use is sucrose, a sweet-tasting disaccharide made of glucose and fructose.

. Functions of nucleotides and their derivatives?

DNA and RNA forming for building blocks of nucleic acids Stores chemical energy DNA replication and RNA transcription

3. Anatomy of DNA and RNA

DNA: deoxyribose, phosphate, ATGC RNA: ribose, phosphate, AUGC

DNA -

Double stranded polynucleotide formed from 2 separate chains of covalently linked deoxyribonucleotide units. Cells store of genetic information

Polar -

In chemistry, describes a molecule or bond in which electrons are distributed unevenly. r.

5. Where does macromolecule assembly occur?

In the cell with monomers

Hydrophobic -

Nonpolar uncharged molecule that forms no H bonds with water and does not dissolve (water fearing)

Inorganic -

Not composed of C atoms

Ionic bond -

One atom donates electrons to another; both become electronically charged

Proteins are __________ built from amino acids, which each have an amino group and a __________ group attached to the central __________. There are 20 possible __________ that differ in structure and are generally referred to as "R." In solutions of neutral pH, amino acids are __________, carrying both a positive and a negative charge. When a protein is made, amino acids are linked together through __________, which are formed by condensation reactions between the carboxyl end of the last amino acid and the __________ end of the next amino acid to be added to the growing chain.

polypeptides; carboxyl; α-carbon; side chains; ionized; peptide bonds; amino

Lipid bilayer -

thin layer of closely packed sheets of phospholipids; forms structure of membranes

Macromolecule -

Polymer built from covalently linked subunits; includes proteins, nucleic acids, and polysaccharides with a molecular mass greater than a few thousand daltons.

Monomer -

Small molecule that can be linked to others of a similar type to form a larger molecule (polymer).

Amino acid

Small organic molecule containing amino and carboxyl group; building block for proteins

Covalent bond -

Stable chemical link between two atoms produced by sharing one or more pairs of electrons

Describe the anatomy of a nucleotide

Sugar, Phosphate, Base

Electronegativity -

Tendency of an atom to attract electrons

Sequence -

The linear order of monomers in a large molecule—for example, amino acids in a protein or nucleotides in DNA; encodes information that specifies a macromolecule's precise biological function.

ATP -

Activated carrier that is carrier of energy in cells; nucleoside triphosphate composed of adenine, ribose, and 3 phosphates

Noncovalent bond -

Chemical association that does not involve the sharing of electrons; singly they are relatively weak, but they can sum together to produce strong, highly specific interactions between molecules. Examples are hydrogen bonds and van der Waals attractions.

Organic molecule -

Chemical compound that contains carbon and hydrogen.

Hydrolysis -

Chemical reaction cleavage of covalent bond with consumption of water

Condensation reaction -

Chemical reaction where covalent bond formed and water expelled; builds polymers (proteins, polysaccharides, and nucleic acids)

Why could covalent bonds not be used in place of noncovalent bonds to mediate most of the interactions of macromolecules? (page 63 2-9). Hint: start by defining covalent and noncovalent bonds and and thinking about why both are needed

Covalent bonds are too stable to mediate so an enzyme would have to come in to break it off

Electrostatic attraction -

Force draws together oppositely charged atoms. Ionic bonds and attractions between molecules with polar covalent bonds

Hydrophilic -

Forms H bonds with water allowing it to dissolve (water loving)

Molecule -

Group of atoms joined together by covalent bonds.

Describe how the ultracentrifuge helped to settle the debate about the nature of macromolecules. (page 61; figure 2-33)

Separates molecules according to size, separate at different rates creating bands, if smear of different sizes that it is not macromolecule. Band indicates it is

The cell is able to harvest energy from various processes in order to generate ATP molecules. These ATPs represent a form of stored energy that can be used later to drive other important processes. Explain how the cell can convert the chemical energy stored in ATP to generate mechanical energy; for example, changing the shape of a protein.

It is seen that an ATP molecule generated by aerobic metabolism of glucose and other metabolic processes, contains three high energy phosphate bonds. Out of these three high energy bonds, two of them can be broken and recreated according to the need of the cell. When these high energy phosphate bonds are broken, huge amount of energy is liberated. This liberation of energy also occurs in the form of progress of phosphorylation of a component of a protein molecule. Phosphorylation of that protein molecule leads to its conformational change which gives rise to mechanical movements. So, it can be said that chemical energy has been converted into mechanical energy.

Polymer -

Long molecule made by covalently linking multiple identical or similar subunits (monomers).

Protein -

Macromolecule built from amino acids that provides cells with their shape and structure and performs most of their activities.

Fatty acid -

Molecule consists of carboxylic acid attached to long hydrocarbon chain. Main source of energy during metabolism and as starting point for synthesis of phospholipids

RNA -

Molecule produced by the transcription of DNA; usually single-stranded, it is a polynucleotide composed of covalently linked ribonucleotide subunits. Serves a variety of informational, structural, catalytic, and regulatory functions in cells.

4. Compare and contrast different types of macromolecules

Proteins: amino acids, provide different functions, enzymes speed up reactions Lipids: fatty acids, C and H, store energy, fats and oils, separates fats, Carbohydrates: monosaccharides, CHO, source of energy, sugars, structural support for cell Nucleic acids: nucleotides, genetic info, make up genes

Hydrogen bond -

Weak noncovalent interaction between positively charged H atom in one and negatively charged atom (N or O0 in another; key to water

Van der Waals attraction -

Weak noncovalent interaction, due to fluctuating electrical charges, that comes into play between two atoms within a short distance of each other