Problem 16 - Biology Today and Tomorrow Without Physiology

Question

Match each molecule with its most suitable description. __________chain of amino acids __________energy carrier in cells __________glycerol, fatty acids, phosphate __________two strands of nucleotides one or more sugar monomers __________richest source of energy __________hydrophilic __________number of protons in nucleus __________molecular jiggling a. polar b. phospholipid c. temperature d. DNA e. ATP f. triglycerides g. atomic number h. carbohydrate i. polypeptide

Step-by-Step Solution

Answer

i, e, b, d, h, f, a, g, c

Step 1: Identify the Descriptions

Read through the given descriptions: chain of amino acids, energy carrier in cells, glycerol/fatty acids/phosphate, two strands of nucleotides, one or more sugar monomers, richest source of energy, hydrophilic, number of protons in nucleus, and molecular jiggling.

Step 2: Match Description with Options - Part 1

For 'chain of amino acids', we recognize this describes a protein structure, so it's matched with 'polypeptide'. Thus, i = chain of amino acids.

Step 3: Match Description with Options - Part 2

For 'energy carrier in cells', the molecule that stores and transfers energy within cells is ATP. Thus, e = energy carrier in cells.

Step 4: Match Description with Options - Part 3

For 'glycerol, fatty acids, phosphate', these components are typically found in phospholipids. Thus, b = glycerol, fatty acids, phosphate.

Step 5: Match Description with Options - Part 4

For 'two strands of nucleotides', this describes the structure of DNA. Thus, d = two strands of nucleotides.

Step 6: Match Description with Options - Part 5

'One or more sugar monomers' is a description of carbohydrates. Thus, h = one or more sugar monomers.

Step 7: Match Description with Options - Part 6

For 'richest source of energy', triglycerides are known for being energy-rich. Thus, f = richest source of energy.

Step 8: Match Description with Options - Part 7

For 'hydrophilic', the term 'polar' typically describes molecules that are hydrophilic. Thus, a = hydrophilic.

Step 9: Match Description with Options - Part 8

For 'number of protons in nucleus', this is the atomic number. Thus, g = number of protons in nucleus.

Step 10: Match Description with Options - Part 9

'Molecular jiggling' refers to the concept of temperature at the molecular level. Thus, c = molecular jiggling.

Key Concepts

Amino Acids

Amino acids are the building blocks of proteins and play a crucial role in various biological processes. They consist of a basic amino group (NH_2), an acidic carboxyl group (COOH), a hydrogen atom, and an organic side chain unique to each amino acid.
These components around a central carbon create the structure of an amino acid. Amino acids link together via peptide bonds to form long chains, known as polypeptides. These polypeptides then fold into specific shapes to become functional proteins, which are indispensable for the structure, function, and regulation of the body’s tissues and organs.

• Proteins are essentially one or more polypeptide chains folded into a unique shape.
• There are 20 different standard amino acids that can combine to form these endless protein structures.
• Each amino acid's unique structure allows proteins to perform a wide array of functions in organisms.

Amino acids thus provide the core fundamentals needed to support life at the cellular level.

Energy Carriers

Energy carriers are molecules that store and supply energy for various cellular processes. The most well-known energy carrier is adenosine triphosphate (ATP), which is crucial for nearly all cellular functions.
These molecules capture chemical energy obtained from the breakdown of food molecules and release it to fuel other cellular processes.

• ATP consists of an adenine base, a ribose sugar, and three phosphate groups.
• The bonds between these phosphate groups store a high amount of energy.
• When a cell needs energy, it converts ATP to ADP (adenosine diphosphate) by breaking one phosphate bond, releasing the stored energy for use.

Thus, ATP serves as the primary energy currency of the cell, allowing it to carry out essential tasks like mechanical work and chemical synthesis.

Nucleotides

Nucleotides are organic molecules that serve as the building blocks for forming nucleic acids such as DNA and RNA. Each nucleotide is composed of three components: a nitrogenous base, a five-carbon sugar (either ribose or deoxyribose), and one or more phosphate groups.

• Nitrogenous bases are categorized into purines (adenine, guanine) and pyrimidines (cytosine, thymine, uracil).
• In DNA, two strands of nucleotides coil around each other to form a double helix structure.
• The sequence of these nucleotides encodes genetic information crucial for the proper functioning of all living cells.

Nucleotides are essential not only for storing genetic information but also for roles in cell signaling and metabolism.

Sugar Monomers

Sugar monomers, or simple sugars, are the basic building blocks of carbohydrates and are needed for many biological processes. These molecules often serve as a key source of energy and play a role in cell structure.
Common examples of sugar monomers include glucose, fructose, and galactose.

• Monosaccharides are the simplest form of sugar and can combine to form disaccharides (like sucrose or lactose) or polysaccharides (like starch or cellulose).
• These sugars are critical as an immediate energy source for cellular respiration.
• They also contribute to the structural framework of cells and tissues in both plants and animals.

Through their versatility and essential functionality, sugar monomers are vital for sustaining cellular energy and metabolism.