Name: cell chemistry: water, ions, and molecules
Uploaded: 2023-04-30T18:28:47.000Z
Duration: 2 min 58 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

NC K-12 Science Standard Course of Study

9-12

Biology

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms- Structures and Processes

LS.Bio.1.1

Chemistry of the Cell

Cells are the basic building blocks of living organisms. They are composed mostly of water, organic molecules, and inorganic ions.
Water makes up around 70% of the cell. This aqueous environment in the cytoplasm is essential for the cell&#8217;s structure and for many of the reactions that occur within it.
Water is a highly polar molecule, so it will interact with other polar molecules and ions in the cell but not with the nonpolar ones.
The hydrophilic environment of the cytoplasm promotes the formation of proteins&#8217; three-dimensional structures, with nonpolar amino acids at the core and polar ones at the surface.
In the case of membrane formation, polar head groups of phospholipids interact with water. In contrast, the nonpolar tails interact with each other creating a hydrophobic barrier to the outside of the cell.
The pH of biological fluids in the cell and its compartments is precisely buffered. The pH of the cytoplasm is around 7.2 and is regulated by molecules such as phosphate ions.
In contrast, the pH in the lysosomes, specialized cellular compartments, is around 5. This is because lysosomes contain enzymes that function optimally in acidic environments.
Organic molecules in the cell include carbohydrates, proteins, lipids, and nucleotides. All of these various macromolecules have a variety of roles.
Carbohydrates are a primary source of energy to power various metabolic processes; however, the cell can break down proteins and lipids for fuel as well.
Proteins can be enzymes that catalyze reactions, or they can contribute to cell structure.
Lipids are a significant component of cell membranes. Additionally, these macromolecules can covalently bond to each other to form conjugates such as glycoproteins and glycolipids, often found in cell membranes.
Nucleotides serve as the genetic material and also associate with proteins to form nucleoproteins that tightly package the DNA in a cell. The nucleotide ATP is also the source of energy for many cellular processes.
Inorganic ions critical to cell function include sodium, potassium, magnesium, calcium, phosphate, and chloride. Although these ions constitute less than 1% of the cell mass, they have diverse roles within the cell.
For example, ions such as calcium are used to relay biological signals throughout a cell, while magnesium is essential for many enzymes&#8217; catalytic activity.

chemistry of the cell

The cell is chemically composed of water, organic molecules and inorganic ions.
Water
The polarity of the water molecule and its resulting hydrogen bonding makes water a unique substance with special properties that are intimately tied to the processes of life. Life originally evolved in an aqueous environment, and most of an organism&#8217;s cellular chemistry and metabolism occur inside the aqueous contents of the cell&#8217;s cytoplasm. Special properties of water are its high heat capacity and heat of vaporization, its ability to dissolve polar molecules, its cohesive and adhesive properties, and its dissociation into ions that leads to the basis of pH. Understanding these characteristics of water helps to elucidate its importance in maintaining life.
One of water&#8217;s important properties is that it is a polar molecule: the hydrogen and oxygen within water molecules (H2O) form polar covalent bonds. While there is no net charge to a water molecule, water&#39;s polarity creates a slightly positive charge on hydrogen and a slightly negative charge on oxygen, contributing to water&#8217;s properties of attraction. Water generates charges because oxygen is more electronegative than hydrogen, making it more likely that a shared electron would be near the oxygen nucleus than the hydrogen nucleus, thus generating the partial negative charge near the oxygen.
As a result of water&#8217;s polarity, each water molecule attracts other water molecules because of the opposite charges between water molecules, forming hydrogen bonds. Water also attracts or is attracted to other polar molecules and ions. A polar substance that interacts readily with or dissolves in water is hydrophilic. In contrast, nonpolar molecules such as oils and fats do not interact well with water. These nonpolar compounds are hydrophobic.
Organic molecules 
Proteins, carbohydrates, nucleic acids, and lipids are the four major classes of biological macromolecules&#8212;large molecules necessary for life that are built from smaller organic molecules. Macromolecules are composed of single units scientists call monomers that are joined by covalent bonds to form larger polymers. The polymer is more than the sum of its parts: it acquires new characteristics and leads to an osmotic pressure that is much lower than that formed by its ingredients. This is an important advantage in maintaining cellular osmotic conditions. A monomer joins with another monomer with water molecule release, leading to a covalent bond forming. Scientists call these dehydration or condensation reactions. When polymers break down into smaller units (monomers), they use a water molecule for each bond broken by these reactions. Such reactions are hydrolysis reactions. Dehydration and hydrolysis reactions are similar for all macromolecules, but each monomer and polymer reaction is specific to its class. Dehydration reactions typically require an investment of energy for new bond formation, while hydrolysis reactions typically release energy by breaking bonds.
Carbohydrates Carbohydrates are a group of macromolecules that are a vital energy source for the cell and provide structural support to plant cells, fungi, and all of the arthropods that include lobsters, crabs, shrimp, insects, and spiders. Carbohydrates can be classified into monosaccharides, disaccharides, and polysaccharides. Glucose storage, in the form of polymers like starch or glycogen, makes it slightly less accessible for metabolism; however, this prevents it from leaking out of the cell or creating a high osmotic pressure that could cause the cell to uptake excessive water.
Proteins Proteins are a class of macromolecules that perform a diverse range of functions for the cell. They help in metabolism by acting as enzymes, carriers, or hormones and provide structural support. The building blocks of proteins are amino acids.
Lipids Lipids are a class of macromolecules that are nonpolar and hydrophobic in nature. Major types include fats and oils, waxes, phospholipids, and steroids. Fats are a stored form of energy and are also known as triacylglycerols or triglycerides. Cholesterol is a type of steroid and is an important constituent of the plasma membrane, where it helps to maintain the membrane&#39;s fluid nature.
Nucleic acids Nucleic acids are molecules composed of nucleotides that direct cellular activities such as cell division and protein synthesis. There are two types of nucleic acids: DNA and RNA. DNA carries the cell&#39;s genetic blueprint and passes it on from parents to offspring. RNA is involved in protein synthesis and its regulation.
Inorganic ions
Inorganic ions constitute less than 1% of the cell mass but are critical to cell function. Those found in a cell include sodium, potassium, magnesium, calcium, phosphate, and chloride.
This text has been adapted from <a href="https://openstax.org/details/books/biology-2e">Openstax, Biology 2e, Unit 1: </a><a href="https://openstax.org/details/books/biology-2e">The Chemistry of Life</a>.

The cell is chemically composed of water, organic molecules and inorganic ions.
Water
The polarity of the water molecule and its resulting hydrogen ...

Education

JoVE Core

Cell Biology

Unit 1

Biochemistry of the Cell

KEY TERMS AND CONCEPTS

cell chemistry: water, ions, and molecules

Cell chemistry explains the substances that make cells work. Water is the main component of cells, and it supports the chemical reactions that keep life going. Cells also contain organic molecules, which are carbon-based compounds, and inorganic ions, which are charged particles needed for cell function.

Organic molecules in cells include carbohydrates, lipids, proteins, and nucleic acids. These molecules have different roles, but together they build cell structures, store energy, and carry genetic information. Inorganic ions also matter because they help cells maintain balance and support key processes.

A cell’s chemistry depends on how these substances interact. Water provides the setting for reactions, while organic molecules and inorganic ions give cells their form and function. Understanding cell chemistry helps explain how living cells stay organized and active.

Cell Chemistry: Water, Ions, and Molecules

the periodic table and organismal elements

the-periodic-table-and-organismal-elements

Elements in the Human Body and Periodic Table

Elements are the smallest units of matter that cannot be broken down further by chemical processes. Scientists know 118 elements, but not all of them occur naturally. Only a small number are essential for life, and living matter depends mostly on carbon, nitrogen, hydrogen, and oxygen. The periodic table organizes elements by their physical and chemical properties. Each square shows the element name, chemical symbol, atomic number, and atomic weight. The atomic number is the number of protons...

functional groups

Functional Groups in Organic Molecules

Functional groups are the part of an organic molecule that gives it specific chemical behavior. They help explain why compounds with similar carbon skeletons can react in different ways. In organic chemistry, these groups are often used to classify compounds. A functional group can change the properties of a molecule and affect how it behaves in a reaction. Knowing functional groups helps students recognize patterns in organic compounds. It also makes it easier to compare molecules that share...

types of chemical bonds

Chemical Bonds and How Atoms Join

Chemical bonds hold atoms together and help explain how different substances form. In chemistry, the main bond types are ionic bonds, covalent bonds, and metallic bonds. Ionic bonds form when electrons move from one atom to another. Covalent bonds form when atoms share electrons. Metallic bonds occur in metals, where electrons are held in a shared arrangement that gives metals their characteristic behavior. Understanding these bond types helps students compare how atoms connect in different...

noncovalent attractions in biomolecules

Biomolecule Interactions Without Covalent Bonds

Biomolecules often stay together through noncovalent attractions instead of covalent bonds. These weaker interactions help molecules recognize each other and form structures needed for life. The main noncovalent attractions are hydrogen bonds, electrostatic interactions, van der Waals forces, and hydrophobic interactions. Each one works in a different way, but all of them can influence how biomolecules fold, bind, and behave in cells. Hydrogen bonds form when a hydrogen atom is attracted to...

polymers

Polymer Chains and Their Properties

Polymers are large molecules made from repeating units called monomers. These long chains can form many common materials. Their structure helps explain why different polymers can behave in different ways. Polymers can be built in more than one way. Some form by addition polymerization, where monomers join together directly. Others form by condensation polymerization, which releases a small molecule as the chain grows. The type of polymer affects its properties and uses. Some polymers are...

what are lipids?

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Lipids are important cell molecules that act as membrane parts, energy stores, and signaling molecules. They are a diverse group of hydrocarbons, which are compounds made of carbon and hydrogen atoms. The carbon-carbon and carbon-hydrogen bonds are nonpolar, so lipids have an overall nonpolar character. Lipids are also hydrophobic, or “water-hating.” They do not form hydrogen bonds with water, so they are nearly insoluble in water. They are, however, soluble in organic solvents such as...

structure of lipids

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chemistry of carbohydrates

Carbohydrate Structure and Bonding

Carbohydrates are built from sugar units and the bonds that link them. Their chemistry explains how simple sugars join to form larger molecules. It also helps show why carbohydrates have different structures and functions. The video focuses on the main sugar types found in carbohydrates. These include monosaccharides, disaccharides, and polysaccharides. Monosaccharides are single sugar units. Disaccharides contain two sugar units, while polysaccharides are long chains of many sugar units. The...

nucleic acids

DNA and RNA in Cells

DNA and RNA are nucleic acids that help store and use genetic information in cells. They are key molecules in biology and are often studied together because they work as a pair in living systems. Nucleic acids are built from repeating units called nucleotides. Each nucleotide has a sugar, a phosphate group, and a nitrogenous base. The order of these bases carries the genetic code. There are two main nucleic acids: DNA, or deoxyribonucleic acid, and RNA, or ribonucleic acid. DNA usually stores...

protein and protein structures

How Protein Shape Determines Function

Proteins are essential molecules in living things, and their shape affects how they work. Protein structure is described at several levels, including primary, secondary, tertiary, and quaternary structure. These levels help explain how a protein is built and how its final form supports its job. Primary structure is the sequence of amino acids in a protein. Secondary structure forms when parts of the chain fold into regular patterns. Tertiary structure is the overall three-dimensional shape of...

ph regulation in cells

Cell pH and Organelle Balance

Cell pH and organelle balance are essential for normal cell function. pH affects protein shape and activity, the charge on cell membranes, and many metabolic reactions inside the cell. Cells also use the proton motive force, which is the energy stored in a proton gradient, to make ATP, the cell’s main energy molecule. The cytosol, or fluid inside the cell, is usually slightly more acidic than the fluid outside the cell. Even so, cells must stop the cytosol from becoming too acidic. They use...

Cell chemistry explains the substances that make cells work. Water is the main component of cells, and it supports the chemical reactions that keep life going. Cells also contain organic molecules, which are carbon-based compounds, and inorganic ions, which are charged particles needed for cell function. Organic molecules in cells include carbohydrates, lipids, proteins, and nucleic acids. These molecules have different roles, but together they build cell structures, store energy, and carry...

key terms and concepts

Explore the chemistry of cells through water, organic molecules, and inorganic ions. Learn how these substances help cells function and stay organized.

Cell Chemistry: Water, Ions, and Molecules | JoVE K12

cell biology

JoVE Core Cell Biology illustrates complex cellular processes in easy-to-understand yet comprehensive animated video lessons. This collection focuses on the essential components and functions of cells, including organelles and membranes, cellular transport, and cell energetics. It is complemented by scientist-in-action videos that demonstrate the application of cell biology in real-world research experiments.

Virginia  Standards of Learning

HIgh School

BIO.2

BIO.2.b

BIO.6

BIO.6.a

Alabama Course of Study Science

From Molecules to Organisms: Structures and Processes

9-12.B.1.1

Compounds Essential to Human Function

The human body is composed of cells that are fundamentally made up of several different molecules. These molecules are essential to carry out all ...

Macromolecules

Biomolecules
Organisms contain a wide variety of organic molecules with numerous functions which depend on the chemical structures and properties of these ...

Solution Preparation
ExpandCAUTION: It is important to always use care when handling reagents. For example, iodine will stain clothes and skin so wear ...

Identifying Macromolecules with Indicator Solutions
ExpandHYPOTHESES: In this activity, the experimental hypothesis might be that the addition of an ...

pH Regulation in Cells

pH plays a critical role in maintaining normal cellular activities. It helps maintain the structure and function of various proteins, dictates the charge ...

Overview of Functional Groups

Functional groups are a group of atoms with characteristic properties, which when linked to the carbon skeleton of a molecule, alter the properties of ...

Introduction to Carbohydrates

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Carbohydrate Metabolism

Sugars as Energy Storage Molecules

What are Lipids?

lipid-derived-compounds-in-the-human-body

Lipid-derived Compounds in the Human Body

Fats and lipids are crucial components in the human body. Some lipid-derived compounds, such as fat-soluble vitamins, eicosanoids, lipoproteins, and ...

Fats as Energy Storage Molecules

What are Proteins?

Protein Organization

Globular Proteins

In organisms, proteins are the most abundant macromolecules. They act as the building blocks of life and play various crucial roles in the body. Proteins ...

Fibrous Proteins

Fibrous proteins are either long and narrow proteins or assemble to form long and thin structures. They contain repetitive units and usually consist of ...

Protein Denaturation

The function of proteins depends on their native three-dimensional structure, which is dictated by the amino acid sequence of the specific protein. ...

Role of Proteins in the Human Body

Proteins are the building block of life. They are also&#160; the most abundant macromolecules with as many diverse roles in the body. They are part of ...

Nucleic Acids and Nucleotides

Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell&#39;s genetic blueprint and have instructions for its ...

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group ...

ATP Energy Storage and Release

ATP and Macromolecule Synthesis

Biological macromolecules are organic compounds, predominantly composed of carbon atoms. The carbon atoms are covalently bonded with hydrogen, oxygen, ...

Construct an explanation to illustrate relationships between structure and function of major macromolecules essential for life.

Introduction to Enzymes

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Enzymes and Activation Energy

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Introduction to Enzyme Kinetics

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Turnover Number and Catalytic Efficiency

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Catalytically Perfect Enzymes

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introduction-to-mechanisms-of-enzyme-catalysis

Introduction to Mechanisms of Enzyme Catalysis

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Ligand Binding and Linkage

Cooperative Allosteric Transitions

Ribozymes

Carry out investigations to illustrate how enzymes act as catalysts for biochemical reactions and how environmental factors affect enzyme activity.

LS.Bio.1.2

What are Cells?

Cells are the smallest and basic units of life, whether it is a single cell that forms the entire organism, e.g., in a bacterium or trillions of them, ...

Cell Size

Cell sizes vary widely among and within organisms. Bacterial cells range between 1-10 micrometers (&#x3BC;m)and are considerably smaller than most ...

Eukaryotic Compartmentalization

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry ...

Prokaryotic Cells

Prokaryotes are small unicellular organisms that include the domains&#x2014;Archaea and Bacteria. Bacteria include many common organisms, such as ...

Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

Endoplasmic Reticulum

Endoplasmic ReticulumThe endoplasmic reticulum (ER) is an extensive network of membranous sacs and tubules in eukaryotic cells, continuous with the outer ...

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

Golgi Apparatus

As they leave the Endoplasmic Reticulum (ER), properly folded and assembled proteins are selectively packaged into vesicles. These vesicles are ...

Lysosomes

Lysosomes are membrane-enclosed spherical sacs derived from the Golgi apparatus. The most important function of the lysosome is degrading macromolecules ...

Peroxisomes

Peroxisomes and mitochondria are two important oxygen-utilizing organelles in eukaryotic cells. Mitochondria carry out cellular respiration&#x2014;the ...

Introduction to the Cytoskeleton

Overview of the Cytoskeleton
The cytoskeleton is a network of protein filaments present within the cell, having three distinct filaments ...

Introduction to Actin

Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle ...

Cell Structure

Background
Cells represent the most basic biological units of all organisms, whether it be simple, single-celled organisms like bacteria, or large, ...

overview-of-myosin-structure-and-function

Overview of Myosin Structure and Function

Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with ...

Visualizing Onion and Cheek Cells
ExpandImmediately before the experiment, wash and peel onion bulbs for the class.
Remove the entire brown outer skin and ...

Microtubules

Microtubules are the thickest cytoskeletal filaments with a diameter of 25 nm. In prokaryotic organisms, microtubules are commonly found in locomotory ...

The Structure of Intermediate Filaments

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Types of Intermediate Filaments

The intermediate filaments are an essential component of the cytoskeleton. Presently six types of intermediate filament have been identified. Type I and ...

Gap Junctions

Multicellular organisms employ a variety of ways for cells to communicate with each other. Gap junctions are specialized proteins that form pores between ...

The Extracellular Matrix

In order to maintain tissue organization, many animal cells are surrounded by structural molecules that make up the extracellular matrix (ECM). Together, ...

Tissues

Cells with similar structure and function are grouped into tissues. A group of tissues with a specialized function is called an organ. There are four main ...

Plant Cell Wall

The plant cell wall gives plant cells shape, support, and protection. As a cell matures, its cell wall specializes according to the cell type. For ...

Plasmodesmata

The organs in a multicellular organism&#x2019;s body are made up of tissues formed by cells. To work together cohesively, cells must communicate. One way ...

Use models to explain how the structure of organelles determines its function and supports overall cell processes.

LS.Bio.1.3

Cells are the smallest and basic units of life, whether it is a single cell that forms the entire organism, e.g., in a bacterium, or trillions of them, ...

the-tree-of-life-bacteria-archaea-and-eukaryotes

The Tree of Life - Bacteria, Archaea, and Eukaryotes

Prokaryotes are small unicellular organisms that include the domains &#8212; Archaea and Bacteria. Bacteria include many common microorganisms, such as ...

Prokaryotic vs. Eukaryotic Cells

Prokaryotic and eukaryotic cells represent two fundamental types of cellular organization, differing significantly in structure, complexity, and function. ...

Construct explanations to compare prokaryotic and eukaryotic cells in terms of structures and degree of complexity.

LS.Bio.1.4

The DNA Helix

Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most viruses. DNA ...

The Central Dogma

The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins.
RNA is the Missing Link Between ...

What is Gene Expression?

A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised&#160; of nucleotides and proteins are ...

RNA Structure

The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form ...

Types of RNA

Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse ...

Transcription

Transcription is the synthesis of RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. ...

Bacterial RNA Polymerase

Eukaryotic RNA Polymerases

General Transcription Factors

Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of ...

RNA Polymerase II Accessory Proteins

Construct an explanation to summarize how DNA and RNA direct the synthesis of proteins.

LS.Bio.1.5

Analyze how the relationship between structure and function supports life processes within organisms.

Cell Chemistry: Water, Ions, and Molecules

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