Chapter 3

What functional groups are found at the N-terminus and the C-terminus of a polypeptide?

- A carboxyl group is at the C-terminus. - An amino group is at the N-terminus.

Descriptions of DNA:

- Contains deoxyribose. - Stores genetic information in cells. - Contains adenine and guanine.

Descriptions that apply to DNA:

- Contains deoxyribose. - Stores genetic information in cells. - Contains adenine and guanine.

Structural components of RNA:

- Cytosine - Uracil - Ribose - Adenine - Guanine

How do fatty acids found in fats and other lipids differ from one another?

- Fatty acids differ in the presence or amount of double bonds. - Fatty acids differ in length of the hydrocarbon chain.

Parts that make up the polar hydrophilic region of a phospholipid molecule:

- Glycerol backbone - Charged nitrogen-containing region - Phosphate group

Which polysaccharides are used for energy storage in cells?

- Glycogen - Starch

What types of bonds are broken when a protein is denatured?

- Hydrogen bonds - Disulfide bonds - Ionic bonds

Interactions between different proteins can be stabilized by:

- Hydrophobic interactions - Polar interactions - Van der Waals forces - Hydrogen bonds

What are 2 possible shapes formed by monosaccharides such as glucose?

- Linear - Ring

What are the major structural components of phospholipids that make them amphipathic?

- Nonpolar fatty acids - Polar phosphate group

Compared to unsaturated fats, Saturated fats:

- Pack together more tightly. - Have a higher melting point.

Why do phospholipids arrange into bilayers?

- The hydrophilic ends attract water while the hydrophobic ends exclude water. - The bilayer is the most energetically favorable arrangement in aqueous solution.

What 4 nitrogenous bases are found in DNA?

- Thymine - Adenine - Cytosine - Guanine

What are the 3 major structural components of amino acid?

1. Amino group 2. R group 3. Carboxyl group

Major class of Lipids with its function in living organisms:

1. Fats: Energy storage. 2. Phospholipids: Plasma membrane structure. 3. Steroids: Form hormones important in reproduction. 4. Waxes: Create a barrier to water loss.

Rank the following Polysaccharides of glucose in order of most branched form (at the tope of the list) to least form (at the bottom of the list):

1. Glycogen 2. Starch 3. Cellulose

What are the 3 basic components of a nucleotide?

1. Nitrogen-containing base 2. Phosphate group 3. Sugar

Amino acid with its chemical characteristics:

1.) Alanine: Nonpolar 2.) Serine: Polar, Uncharge 3.) Aspartic acid: Polar, Negatively (-) charged 4.) Lysine: Polar, Positively (+) charged

What are the 3 atoms found in all carbohydrates?

1.) Carbon 2.) Oxygen 3.) Hydrogen

What 3 polysaccharides play a structural role in organisms?

1.) Glycosaminoglycans 2.) Cellulose 3.) Chitin

What are the 4 categories of macromolecules?

1.) Lipids 2.) Proteins 3.) Carbohydrates 4.) Nucleic Acids

Major Classes of Lipids:

1.) Triglycerides

What are the 2 types of secondary structure found in proteins?

1.) 𝛼 helix 2.) 𝛽 pleated sheet

Describes the chemical structure of steroids?

4 fused rings of carbon with 1 or more attached hydroxyl groups.

Accurately described the chemical structure of a typical amino acid found in a protein?

A central carbon atom is bound to an amino group, carboxyl group, a side chain, and a hydrogen atom.

Different regions of a protein may contribute a particular function to the protein. What is such a part of the proteins called?

A domain

Proteins are made up of chains of _____________________ acids.

Amino acids

What are the monomers found in proteins?

Amino acids

A free _________________ group is found at the N-terminus of a protein, and a free ________________ group is found at the C-terminus.

Amino, Carboxyl

When a peptide bond is formed, 2 amino acids are linked between the _________________ group of one amino acid and the __________________ group of the other.

Amino, Carboxyl

Saturated fats are typically found in ___________________, and Unsaturated fats are more commonly found in ________________.

Animals, Plants

The fatty acid that is polyunsaturated contain 2 or more _____________________________.

C=C bonds

Each macromolecule and its appropriate function:

Carbohydrates: Simpler molecules are broken down to make ATP, while large molecules may store energy or may play a structural role. Lipids: Are key components of cell membranes; Also function as hormones and in energy storage. Proteins: Play a key role in cell structure and carry out diverse array of cellular functions. Nucleic acids: Function in storage of, and access to, genetic information.

Polysaccharide with its function in living organisms:

Cellulose: is the main component of the plant cell wall. Starch: is used for energy storage in plants. Glycogen: is used for energy storage in animals. Chitin: is found in the exoskeletons of insects and crustaceans and in the fungal cell wall. Glycosaminoglycan: is found in the extracellular matrix and cartilage of animals.

All steroid hormone are derived from _______________________.

Cholesterol

The steroid molecule called _______________________ is commonly found in the cellular membranes of animals.

Cholesterol

Where are the complex lipids called waxes typically found?

Cuticles of insects and leaves of plants.

What macromolecule is used for the storage of genetic information in cells?

DNA

The 2 classes of nucleic acids are ________________________ and _______________________.

DNA, RNA

____________ is used by the cell to store genetic information, while ____________ is involved in decoding the genetic information.

DNA, RNA

Proteins are made by _____________________________ reactions, in which water is removed as amino acids are linked together to form polypeptides.

Dehydration reactions

How are fats synthesized?

Dehydration synthesis links 3 fatty acids to glycerol.

The nucleotides of DNA molecules contain the sugar _______________________ as part of the backbone of the molecule.

Deoxyribose

What type(s) of sugar forms the backbone of DNA molecules?

Deoxyribose

How does the presence of a double bond influence the shape of a fatty acid?

Double bonds between carbon molecules introduce kinks in the otherwise linear structure of fatty acids.

The structure of DNA consists of 2 strands coiled around each other to form a structure called a ___________________ ___________________.

Double helix

What type of bond joins fatty acids and glycerol in a fat molecule?

Ester bond

Main reproductive hormone in females?

Estrogen

A chain of carbon and hydrogen atoms with a carboxyl group at one end is called _______________________________________.

Fatty acid

Fats consist of 3 fatty _______________ covalently bonded to a 3-carbon molecule called ____________________.

Fatty acids, Glycerol

Which sugar monomer forms the polysaccharides starch, cellulose, and glycogen?

Glucose

Fats, or triglycerides, are composed of:

Glycerol covalently bound to 3 fatty acids.

What type of bond forms between 2 sugar molecules?

Glycosidic bond

Structural Isomers

Have the same number and types of atoms, but the arrangement of chemical bonds is different.

Lipids are molecules that are composed of primarily what 2 elements?

Hydrogen & Carbon

What type of bond is responsible for the base pairing between 2 strands of DNA in the double helix?

Hydrogen bond

Match each bond and interaction:

Hydrogen bond: are found between partial positive and partial negative charges on different amino acids. Ionic bond: form between oppositely charged amino acid side chains. Disulfide bonds: are covalent bonds that form between 2 cysteines. Hydrophobic effect: is an interaction between non polar amino acids. Van der Waals forces: are weak, temporary interactions between atoms.

The elements of a polypeptide's secondary structure, the 𝛼 helix and 𝛽 pleated sheets are stabilized by ____________________________ bonds.

Hydrogen bonds

Where are the peptide bonds in a polypeptide located?

In the polypeptide backbone.

The C=C double bonds in fatty acids introduce a ____________ into the linear shape of the fatty acid chain.

Kink

Unsaturated fats have _______________________ melting points than saturated fats.

LOWER

What are macromolecules?

Large molecules that are formed by joining smaller molecules together.

_________________________ are small molecules that are linked together to form polymers, such as proteins, polysaccharides, and nucleic acids.

Monomers

Polysaccharides can be hydrolyzed in the presence of water. What is the product of this reaction?

Monosaccharides

What type of monomers are combined to form carbohydrates?

Monosaccharides

Category of Protein with its function:

Motor proteins: initiate movement. Defense proteins: disease protection. Structural proteins: support and strengthen. Transporters: move solutes across plasma membrane.

The main elements that make up proteins are carbon, hydrogen, ______________________, and ______________________, in addition to small amounts of other elements, like sulfur.

Oxygen, Nitrogen

What type of bond forms between 2 amino acids during a dehydration reaction?

Peptide bond

Start is found in ________________ cells and glycogen is found in _________________ cells.

Plant, Animal

In a phospholipid bilayer, the _________________ regions of the phospholipids face water and the ______________________ regions face the interior of the membrane away from the water.

Polar, Nonpolar

Phospholipids are amphipathic because they contain both _____________ and _________________ groups.

Polar, Nonpolar

A protein is composed of one or more ___________________________.

Polypeptides

How are polypeptides numbered?

Polypeptides are numbered from the amino-terminus to the carboxyl-terminus.

When many monosaccharides are linked together to form polymers, the polymers are called ________________________________.

Polysaccharides

The amino acid sequence of a polypeptide is called the ___________________ structure.

Primary structure

What level of protein structure occurs when 2 or more polypeptides interact with each other to form a functional protein?

Quaternary structure

What are regions with NO secondary structure called?

Random coiled regions

Typically, fats found in animals (usually solid) are ________________, while fats found in plants (usually liquid) are ___________________.

Saturated, Unsaturated

Random coiled regions of a polypeptide chain are the regions that lack a _________________________ structure.

Secondary structure

The _____________________ structure of a polypeptide is the repeating pattern of folding stabilized by hydrogen bonds.

Secondary structure

What are stereoisomers?

Stereoisomers have identical bonding relationships but a different spatial arrangement of atoms.

The chemical structure of all _____________________ consists of 4 fused rings of carbon atoms with 1 or more polar hydroxyl groups attached to the ring structure.

Steroids

Individual polypeptides within a protein are referred to was as ______________________.

Subunits

Disulfide bridges are covalent bonds between _____________________ groups of cysteine side chains.

Sulfhydryl groups

Interactions among the side chains of amino acids help to stabilize the _________________________ structure of a polypeptide.

Tertiary structure

The 3 dimensional shape of a polypeptide is the ____________________ structure.

Tertiary structure.

In a peptide bond, which parts of the 2 amino acids are joined together?

The amino group of 1 amino acids and the carboxyl group of the other.

What are sources of variation in lipid molecules?

The length of the fatty acids and presence of double bonds.

What is the function of waxes?

They prevent water loss.

DNA and RNA are made of nitrogenous bases. Both DNA and RNA contain adenine, guanine, and cytosine. In addition, DNA contains the base ___________________, but RNA contains ____________________.

Thymine, Uracil

Which form of unsaturated fatty acids are created during manufacturing processes and pose a risk to human health?

Trans unsaturated fatty acids

Fats, a type of lipid, are also called ___________________________ and contain 3 fatty acids attached to glycerol.

Triglycerides

Oils are fats that are high in _____________________________ fatty acids.

Unsaturated

Which type of fatty acid contain 1 or more C=C double bonds?

Unsaturated fatty acid

RNA differs from DNA in that RNA contains the base ____________ and does not contain the base _______.

Uracil, T

What type of lipid consists of long structures resembling fatty acids attached to each other by their carboxyl groups?

Wax

A phospholipid molecule consists of __________________________________________________________________________________.

a head that is polar and hydrophilic, and 2 tails that are nonpolar and hydrophobic.

𝛼 helices are commonly found in proteins that are:

anchored in a cell's plasma membrane.

Enantiomers

are mirror images. The bonding relationships are the same, but the atoms are positioned differently in a way that makes the Enantiomers mirror images of each other.

Cis-Trans Isomers

have the same chemical formula and the same bonding relationships. However, the atoms are positioned differently around a double bond.

Starch and glycogen are used for _____________________________________ in living cells.

storing energy

Proteins have quaternary structure consists of __________ or more polypeptides.

two (2)