Macromolecules

Polysaccharides

- A long chain of monosaccharides linked by glycosidic bonds - The chain may be branched or unbranched and may contain different types of monosaccharides. The molecular weight of a polysaccharide can be quite high, reaching 100,000 daltons or more if enough monomers are joined. Starch, glycogen, cellulose, and chitin are some major examples of _______________ important in living organisms.

α helix

- the carbonyl (C=O) of one amino acid is hydrogen-bonded to the amino H (N-H) of an amino acid that is four down the chain. - This pattern of bonding pulls the polypeptide chain into a helical structure that resembles a curled ribbon, with each turn of the helix containing 3.6 amino acids. The R groups of the amino acids stick outward from the α helix, where they are free to interact.

codons

A __________________is a trinucleotide sequence of DNA or RNA that corresponds to a specific amino acid. The genetic code describes the relationship between the sequence of DNA bases (A, C, G, and T) in a gene and the corresponding protein sequence that it encodes. The cell reads the sequence of the gene in groups of three bases.

Directionality

A consequence of the structure of nucleotides is that a polynucleotide chain that is, it has two ends that are different from each other.

Structural Isomers

Any of two or more compounds with identical chemical formulas differ structurally in the sequence in which the atoms are linked.

chromosomes

DNA is typically broken up into a number of very long, linear pieces called ___________________, while in prokaryotes such as bacteria, ___________________- are much smaller and often circular (ring-shaped). A__________________________ may contain tens of thousands of genes, each providing instructions on how to make a particular product needed by the cell.

Saturated

If there are only single bonds between neighboring carbons in the hydrocarbon chain, a fatty acid is said to be _______________________ The thing that fatty acids are __________________ with is hydrogen; in a _____________________, as many hydrogen atoms as possible are attached to the carbon skeleton.)

Monounsaturated

If there is just one double bond in a fatty acid

trans Fat

In this process, hydrogen gas is passed through oils (made mostly of cis-unsaturated fats), converting some - but not all - of the double bonds to single bonds. The goal of partial hydrogenation is to give the oils some of the desirable properties of saturated fats, such as solidity at room temperature, but an unintended consequence is that some of the cis double bonds change configuration and become trans double bonds._____________________________________can pack more tightly and are more likely to be solid at room temperature. Some types of shortening, for example, contain a high fraction of trans fats.

Ketone Group

Ketone, any of a class of organic compounds characterized by the presence of a carbonyl group in which the carbon atom is covalently bonded to an oxygen atom.

quaternary structure

Many proteins are made up of a single polypeptide chain and have only three levels of structure. However, some proteins are made up of multiple polypeptide chains, also known as subunits. When these subunits come together, they give the protein its ______________________________________________

peptide bonds

The amino acids of a polypeptide are attached to their neighbors by covalent bonds known as a ____________________. Each bond forms in a dehydration synthesis (condensation) reaction. During protein synthesis, the carboxyl group of the amino acid at the end of the growing polypeptide chain chain reacts with the amino group of an incoming amino acid, releasing a molecule of water. The resulting bond between amino acids is a _______________________________.

Secondary Structure

The next level of protein structure Refers to local folded structures that form within a polypeptide due to interactions between atoms of the backbone.

Tertiary Structure

The overall three-dimensional structure of a polypeptide primarily due to interactions between the R groups of the amino acids that make up the protein.

Primary Structure

The simplest level of protein structure Is simply the sequence of amino acids in a polypeptide chain.

Sugar Phosphate

The sugars and phosphates lie on the outside of the helix, forming the backbone of the DNA; this portion of the molecule is sometimes called the _____________________ backbone.

antiparallel

The two strands of the helix run in opposite directions, meaning that the 5′ end of one strand is paired up with the 3′ end of its matching strand. (This is referred to as ________________orientation and is important for the copying of DNA.)

Denatured

When a protein loses its higher-order structure, but not its primary sequence Denatured proteins are usually non-functional

unsaturated

When the hydrocarbon chain has a double bond, the fatty acid is said to be ____________________________, as it now has fewer hydrogens.

Complementary

When two DNA sequences match in this way, such that they can stick to each other in an antiparallel fashion and form a helix, they are said to be __________________________.

Lipids

a category of molecules united by their inability to mix well with water. ___________ tend to be hydrophobic, nonpolar, and made up mostly of hydrocarbon chains, though there are some variations on this, which we'll explore below. The different varieties of __________ have different structures, and correspondingly diverse roles in organisms. For instance,_______ store energy, provide insulation, make up cell membranes, form water-repellent layers on leaves, and provide building blocks for hormones like testosterone.

phosphodiester linkage

a covalent bond in RNA or DNA that holds a polynucleotide chain together by joining a phosphate group at position 5 in the pentose sugar of one nucleotide to the hydroxyl group at position 3 in the pentose sugar of the next nucleotide

polynucleotide

a linear polymer whose molecule is composed of many nucleotide units, constituting a section of a nucleic acid molecule.

Aldose

a monosaccharide (a simple sugar) with a carbon backbone chain with a carbonyl group on the endmost carbon atom, making it an aldehyde, and hydroxyl groups connected to all the other carbon atoms.

Ketose

a monosaccharide that contains a ketone group

RNA

a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins

Nucleus

a specialized, membrane-bound vault in the cell

michelle

a sphere-shaped structure which the hydrophilic phosphate heads face the outside and the fatty acids face the interior of this structure. Formation of micelle is an energetically favored because it sequesters the hydrophobic fatty acid tails, allowing the hydrophilic phosphate head group to instead interact with the surrounding water

Double Helix

a structure in which two matching (complementary) chains are stuck together

microRNA

act as regulators of other genes, and new types of non-protein-coding RNAs are being discovered all the time

Steroids

are another class of lipid molecules, identifiable by their structure of four fused rings. Although they do not resemble the other lipids structurally, ______________ are included in lipid category because they are also hydrophobic and insoluble in water. All______________have four linked carbon rings and several of them, like cholesterol, also have a short tail. Many _____________ also have an -OH functional group attached at a particular site

small interfering RNAs and siRNAs

are artificially synthesized 19-23 nucleotide long double-stranded RNA molecules. They are routinely used in molecular biology for transient silencing of gene of interest. They elicit RNAi response upon binding to their target transcript based on the sequence complementarity.

Hormones

are long-distance chemical signals released by endocrine cells (like the cells of your pituitary gland). They control specific physiological processes, such as growth, development, metabolism, and reproduction. While some__________________________ are steroid-based, others are proteins. These protein-based _______________________ are commonly called peptide ________________________.

phospholipids

are major components of the plasma membrane. Like fats, they are typically composed of fatty acid chains attached to a backbone of glycerol. Instead having three fatty acid tails, however,_____________________ generally have just two, and the third carbon of the glycerol backbone is occupied by a modified phosphate group. Different _____________________ have different modifiers on the phosphate group, with choline (a nitrogen-containing compound) and serine (an amino acid) being common examples. Different modifiers give __________________different properties and roles in a cell.

Isomers

are molecules with the same chemical formula but have different structures

omega-3

are polyunsaturated fatty acids characterized by the presence of a double bond three atoms away from the terminal methyl group in their chemical structure? from basic precursor forms: alpha-linolenic acid (ALA)

Triglycerides

are primarily stored in specialized fat cells, called adipocytes, which make up a tissue known as adipose tissue

Monosaccharides

are simple sugars, the most common of which is glucose. have a formula of (CH20)n, and they typically contain three to seven carbon atoms.

Amino Acids

are the monomers that make up proteins.

5' end

beginning of the chain

Carbohydrates

biological molecules made of carbon, hydrogen, and oxygen in a ratio of roughly one carbon atom (C) to one water molecule(H20) This composition gives its name: they are made up of carbon (carbo-) plus water (-hydrate).

transfer RNA

cloverleaf-shaped RNA molecules that bring amino acids to the ribosome for protein synthesis

Amylose

consists entirely of unbranched chains of glucose monomers connected by 1-4 linkages

Disulfide bonds

covalent linkages between the sulfur-containing side chains of cysteines, are much stronger than the other types of bonds that contribute to tertiary structure. They act like molecular "safety pins," keeping parts of the polypeptide firmly attached to one another.

3' end

end of the chain

omega-6

family of polyunsaturated fatty acids that have in common a final carbon-carbon double bond in the n-6 position, that is, the sixth bond, counting from the methyl end. from a basic precursor form: linoleic acid (LA)

Deoxryribose

five-carbon sugar molecule that helps form the phosphate backbone of DNA molecules.

Dissacharides

form when two monosaccharides join together via a dehydration reaction, also known as a condensation reaction or dehydration synthesis. In this process, the hydroxyl group of one monosaccharide combines with the hydrogen of another, releasing a molecule of water and forming a covalent bond known as a glycosidic linkage.

carboxyl terminus

has a free carboxyl group, is known as the has a free carboxyl group, is known as the ______________________________.

Pyrimidines

have a single carbon-nitrogen ring

polyunsaturated

if there are multiple double bonds

hydrophobic interactions

in which amino acids with nonpolar, hydrophobic R groups cluster together on the inside of the protein, leaving hydrophilic amino acids on the outside to interact with surrounding water molecules.

Amyloceptin

is a branched polysaccharide. Although most of its monomers are connected by 1-4 linkages, additional 1-6 linkages occur periodically and result in branch points.

Aldehyde

is a compound containing a functional group with the structure −CHO, consisting of a carbonyl center (a carbon double-bonded to oxygen) with the carbon atom also bonded to hydrogen and to an R group, which is any generic alkyl or side chain.

Cellulose

is a major component of plant cell walls, which are rigid structures that enclose the cells (and help make lettuce and other veggies crunchy). Wood and paper are mostly made of ______________, and __________- itself is made up of unbranched chains of glucose monomers linked by 1-4 glycosidic bonds

Denaturation

is a process in which proteins or nucleic acids lose the quaternary structure, tertiary structure, and secondary structure which is present in their native state, by application of some external stress or compound such as a strong acid or base, a concentrated inorganic salt, an organic solvent.

Nucleoid

is an irregularly-shaped region within the cell of a prokaryote that contains all or most of the genetic material. In contrast to the nucleus of a eukaryotic cell, it is not surrounded by a nuclear membrane

DNA

is the genetic material found in living organisms, all the way from single-celled bacteria to multicellular mammals carrier of genetic information

Glycogen

is the storage form of glucose in humans and other vertebrates. Like starch, _________________is a polymer of glucose monomers, and it is even more highly branched than amylopectin. is usually stored in liver and muscle cells. Whenever blood glucose levels decrease, __________________ is broken down via hydrolysis to release glucose monomers that cells can absorb and use.

Starch

is the stored form of sugars in plants and is made up of a mixture of two polysaccharides, amylose and amylopectin (both polymers of glucose).

Nucleic Acids

macromolecules made out of units called nucleotides, come in two naturally occurring varieties: DNA & RNA

amphipathic

meaning it has a hydrophobic part and a hydrophilic part. The fatty acid chains are hydrophobic and do not interact with water, whereas the phosphate-containing group is hydrophilic (because of its charge) and interacts readily with water.

directionality

meaning that it has two ends that are chemically distinct from one another

Fat

molecule consists of two kinds of parts: a glycerol backbone and three fatty acid tails. Glycerol is a small organic molecule with three hydroxyl (OH) groups, while a fatty acid consists of a long hydrocarbon chain attached to a carboxyl group. A typical fatty acid contains 12-18 carbons, though some may have as few as 4 or as many as 36.

polypeptide

one or more linear chains of amino acids

nucleotides

organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth.

Messenger RNA

serves as a messenger between DNA and the ribosomes

Ribose

sugar of RNA

Cholesterol

the most common steroid, is mainly synthesized in the liver and is the precursor to many steroid hormones. These include the sex hormones testosterone and estradiol, which are secreted by the gonads (testes and ovaries). _______________ also serves as the starting material for other important molecules in the body, including vitamin D and bile acids, which aid in the digestion and absorption of fats from dietary sources. It's also a key component of cell membranes, altering their fluidity and dynamics. ___________________ is also found in the bloodstream, and blood levels of ______________ are what we often hear about at the doctor's office or in news reports. __________________ in the blood can have both protective effects (in its high-density, or HDL, form) and negative effects (in its low-density, or LDL, form) on cardiovascular health.

amino terminus

the polypeptide has a free amino group, and this end is called ___________________________________.

Stereoisomers

their atoms are bonded together in the same order, but they have a different 3D organization of atoms around one of their asymmetric carbons.

Purines

two fused carbon-nitrogen rings

β pleated sheet

two or more segments of a polypeptide chain line up next to each other, forming a sheet-like structure held together by hydrogen bonds. The hydrogen bonds form between carbonyl and amino groups of backbone, while the R groups extend above and below the plane of the sheet The strands of a __________________________________ may be parallel, pointing in the same direction (meaning that their N- and C-termini match up), or antiparallel, pointing in opposite directions (meaning that the N-terminus of one strand is positioned next to the C-terminus of the other)

ribosomal RNA

which serve as structural components of ribosomes