scic final

protein

A large, complex molecule made up of amino acids, which are linked together by peptide bonds.

play essential roles in biological processes, including acting as enzymes, hormones, and structural components in cells.

-helix

A common secondary structure in proteins, characterized by a right-handed coil or spiral formed by hydrogen bonding between the backbone atoms.

-sheet

A secondary structure in proteins, consisting of beta strands connected laterally by hydrogen bonds, forming a sheet-like configuration.

essential amino acid

An amino acid that cannot be synthesized by the body and must be obtained from the diet. Essential for various bodily functions, they include leucine, isoleucine, and valine.

complete protein

A protein that contains all nine essential amino acids necessary for the human diet.

active site

The specific region of an enzyme where substrate molecules bind and undergo a chemical reaction. It plays a crucial role in catalyzing biochemical processes.

primary structure of protein

The unique sequence of amino acids in a polypeptide chain, determining the protein's overall structure and function.

secondary structure of protein

characterized by the folding and coiling of the polypeptide chain into patterns such as alpha helices and beta sheets, stabilized by hydrogen bonds.

tertiary structure of protein

The three-dimensional shape of a protein that results from the interactions between the amino acid side chains. This structure is critical for the protein's function and is stabilized by various bonds, including hydrogen bonds, ionic bonds, and disulfide bridges.

denaturation

The process in which a protein loses its native structure due to the disruption of various bonds, often caused by factors such as heat, pH changes, or chemical agents.

Uses of protein

Proteins serve numerous vital functions in the body, including catalyzing biochemical reactions as enzymes, providing structural support in cells and tissues, transporting molecules, and regulating biological processes like immune responses and hormonal regulation.

Condensation reaction to make proteins from amino acids

The process called transcription whereby amino acids are linked together, forming peptide bonds, resulting in the formation of proteins.

How proteins function as enzyme

by acting as biological catalysts that increase the rate of chemical reactions without being consumed. They bind to substrates to form enzyme-substrate complexes, lowering the activation energy required for reactions.

Why protein structure is disrupted by heating, acid, or alcohol

can disrupt protein structure by denaturing proteins, breaking hydrogen bonds, ionic bonds, and hydrophobic interactions that maintain the protein's three-dimensional shape, ultimately affecting its function.

DNA

is the molecule that carries genetic information in living organisms, consisting of two strands that coil around each other to form a double helix. It encodes the instructions for the development and function of all known life forms.

nucleotide

is the basic building block of nucleic acids, consisting of a nitrogenous base, a five-carbon sugar, and one or more phosphate groups. Nucleotides link together to form the strands of DNA and RNA.

bases (ATGC)

adenine (A), thymine (T), guanine (G), and cytosine (C), which pair specifically (A with T, G with C) to form the genetic code.

expression

is the process by which the information from a gene is used to synthesize a functional gene product, typically a protein. This involves transcription and translation.

transcription

is the process of copying a segment of DNA into RNA, which serves as a template for protein synthesis during translation.

translation

the process of synthesizing proteins from mRNA by ribosomes, where the genetic code is decoded to assemble amino acids into a polypeptide chain.

complementarity

refers to the specific pairing of nucleotides in DNA and RNA, ensuring accuracy in the synthesis of RNA from DNA during transcription and the formation of protein from mRNA.

base pair

comprises two nucleotides on opposite complementary DNA or RNA strands that are linked by hydrogen bonds, pivotal for the structure of DNA and fidelity in genetic information transfer.

gene

a segment of DNA that contains the instructions for synthesizing a specific protein, playing a crucial role in heredity and the expression of traits.

codon

a sequence of three nucleotides in mRNA that correspond to a specific amino acid or signal the termination of protein synthesis, playing a critical role in translating genetic information into proteins.

intron

a non-coding segment of a gene that is transcribed into RNA but is removed during RNA processing before translation into protein.

exon

a segment of a gene that codes for a protein and is expressed in the final mRNA transcript after introns have been removed.

virus

a microscopic infectious agent that can only replicate inside a living host cell. Viruses consist of genetic material surrounded by a protein coat and can infect various organisms, including animals, plants, and bacteria.

mutation

a change in the DNA sequence that may alter gene function or expression.

cloning

the process of producing identical copies of an organism or cell by asexual reproduction or laboratory techniques.

polymerase chain reaction (PCR

is a laboratory technique used to amplify specific DNA sequences, allowing millions of copies to be generated from a small initial sample.

recombinant DNA

is a form of DNA that has been artificially created by combining genetic material from different sources, often used in genetic engineering.

genetically modified foods

are food products that have been altered using genetic engineering techniques to enhance desired traits such as resistance to pests or improved nutritional content.

double blind trial,

is a study design in which neither the participants nor the researchers know who belongs to the control or experimental group, minimizing bias and ensuring more reliable results.

COX-1

is an enzyme that helps produce prostaglandins, which are involved in protecting the stomach lining and regulating blood platelets.

COX-2

is an enzyme that plays a significant role in inflammation and pain; it is often targeted by nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce these symptoms.

Know DNA structure

consisting of two strands forming a double helix structure composed of nucleotides.

subunits from which DNA is made

are called nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base.

How DNA structure make replication possible

The double helix structure of DNA allows for the strands to separate, enabling each strand to serve as a template for the synthesis of a new complementary strand. This semi-conservative mechanism ensures accurate replication of genetic information.

Explain how DNA replicates

occurs through a semi-conservative process where each original strand serves as a template for a new complementary strand, resulting in two identical DNA molecules.

Why A only pairs with T and G with C

This pairing is due to the specific hydrogen bonding patterns between the nitrogenous bases; adenine (A) forms two hydrogen bonds with thymine (T), while guanine (G) forms three hydrogen bonds with cytosine (C), ensuring fidelity in DNA structure and function.

Explain simply how genes are expressed

through the processes of transcription and translation, where DNA is first transcribed into messenger RNA (mRNA), which is then translated into proteins that perform various functions in the cell.

Gene therapy as given in the cystic fibrosis example

is a technique that modifies genes to treat or prevent diseases, such as cystic fibrosis, by correcting or replacing the defective gene responsible for the disorder, thereby restoring normal function.

Two types of drugs (kill infectious agents; produce physiological response)

are known as antimicrobial agents and pharmacological drugs, respectively. Antimicrobials target pathogens, while pharmacological drugs induce specific bodily functions.

Use the aspirin & VIOXX/Celebrex example of explaining how drugs work

Aspirin inhibits COX-1 and COX-2 enzymes to reduce pain and inflammation, while VIOXX/Celebrex selectively inhibits COX-2, targeting inflammation with fewer gastrointestinal side effects.

Solute

is a substance that is dissolved in a solvent to create a solution. It can be a solid, liquid, or gas that undergoes dissolution.

solvent

a substance that dissolves a solute to form a solution, typically liquid.

solution

a uniform mixture of solute and solvent.

solubility

the ability of a substance to dissolve in a solvent

saturated solution

a solution that contains the maximum amount of solute that can dissolve at a given temperature.

electrolyte

A substance that produces ions in solution, thereby conducting electricity.

acid

a substance that donates protons (H+) in a chemical reaction and increases the concentration of hydronium ions in a solution. Acids typically have a sour taste and can turn blue litmus paper red.

base

a substance that can accept protons or donate electron pairs in reactions.

strong acids

acids that completely dissociate in water, releasing all their protons and resulting in a high concentration of hydronium ions.

weak acids

acids that partially dissociate in water, leading to a lower concentration of hydronium ions compared to strong acids.

strong base

a substance that can completely dissociate in solution to accept protons or donate electron pairs, resulting in a high concentration of hydroxide ions.

weak base

a substance that partially dissociates in solution to accept protons or donate electron pairs, resulting in a lower concentration of hydroxide ions compared to strong bases.

indicator

a substance that changes color in response to changes in pH, helping to identify the acidity or basicity of a solution.

buffer

a solution that resists changes in pH upon the addition of small amounts of acids or bases, typically composed of a weak acid and its conjugate base.

Unique properties of water

high boiling point, expand on freezing, ability to dissolve ions

how the properties of water relate to hydrogen-bonding

Hydrogen bonding gives water its unique properties, such as a high boiling point due to stronger intermolecular attractions, expansion upon freezing as ice forms a crystalline structure, and the ability to dissolve a variety of ions and polar substances.

Solubility

the ability of a substance to dissolve in a solvent to form a homogeneous mixture.

hard water

water that contains high levels of dissolved minerals, particularly calcium and magnesium.

what ions cause hard water

Calcium and magnesium ions.

How solutes change freezing point and boiling point

by lowering the freezing point and raising the boiling point, a phenomenon known as freezing point depression and boiling point elevation.

Conductivity

ability of solution to conduct electricity depends on ions

properties of acids

sour taste, pH below 7, and the ability to donate protons (H+) in a solution.

properties of bases

bitter taste, slippery feel, pH above 7, and the ability to accept protons (H+) in a solution.

Understand the autoionization reaction of water

Water dissociates into hydrogen ions (H+) and hydroxide ions (OH-) in equilibrium.

equilibrium relationship

The relationship between the concentrations of reactants and products in a reversible chemical reaction at equilibrium.

Know the strong acids

HCl, HNO3, H2SO4

Know the strong bases

NaOH, KOH, LiOH

Write reactions for how acids form H+ and bases form OH–

Acids donate protons (H+) in water, while bases accept protons or donate hydroxide ions (OH–), leading to neutralization reactions.

Know the reaction of acid-base neutralization

Acid-base neutralization occurs when an acid reacts with a base to produce water and a salt, typically releasing heat in the process.

What buffers do, and why

resist changes in pH by absorbing excess H+ or OH– ions. They consist of a weak acid and its conjugate base, helping maintain stable pH levels in biological systems.

Oxidation

is the process of losing electrons, often involving the increase of oxidation states in chemical reactions, typically associated with the addition of oxygen or the removal of hydrogen.

reduction

the gain of electrons or decrease in oxidation state, often involved in redox reactions.

Oxidation-reduction reaction

is a chemical reaction that involves the transfer of electrons between two species, where one undergoes oxidation and the other undergoes reduction.

half-reaction

is either the oxidation or reduction part of a redox reaction, showing the transfer of electrons.

oxidizing agent

A substance that gains electrons in a redox reaction, causing the oxidation of another species.

reducing agent

is a substance that donates electrons in a redox reaction, causing another species to be reduced.

anode

the electrode where oxidation occurs in an electrochemical cell.

cathode

The electrode where reduction occurs during electrochemical reactions.

primary battery

A type of electrochemical cell that provides electrical energy from a spontaneous chemical reaction and cannot be recharged. Commonly used in applications where replacement is more practical than recharging.

secondary battery

A rechargeable electrochemical cell that can be used multiple times by restoring its chemical energy through an external electrical source. Commonly used in applications such as electric vehicles and portable electronics.

uel cell,

A device that converts chemical energy into electrical energy through a reaction between fuel and an oxidizer, often used in energy applications.

carbon economy

An economic system focused on reducing carbon emissions by transitioning to renewable energy and sustainable practices.

hydrogen economy

A proposed system where hydrogen is used as a primary energy carrier, replacing fossil fuels and emphasizing renewable energy sources.

Understand parts of an electrochemical cell

The components of an electrochemical cell include the anode, cathode, electrolyte, and external circuit, which facilitate the flow of electrons during chemical reactions.

Differences between primary battery, secondary battery

Primary batteries are non-rechargeable, whereas secondary batteries can be recharged and reused multiple times.

Differences between a “dry cell” and an “alkaline battery”

A "dry cell" refers to a type of primary battery that uses a paste electrolyte, while an "alkaline battery" is a specific type of dry cell that uses an alkaline electrolyte, providing higher energy density and longer shelf life.

Advantages/Disadvantages of “hydrogen economy

The hydrogen economy refers to the use of hydrogen as a fuel source, which has advantages such as producing only water as a byproduct when burned, and potential for renewable production. However, it also has disadvantages, including high production costs, challenges in storage and transport, and the need for a robust infrastructure.

Advantages and technological hurdles to fuel-powered cars

Fuel-powered cars offer advantages such as greater range and faster refueling compared to electric vehicles. However, they face technological hurdles including reliance on fossil fuels, emissions concerns, and the need for advancements in fuel efficiency and alternative fuels.

Element

A pure substance consisting of one type of atom that cannot be broken down chemically.

atom

The basic unit of matter consisting of a central nucleus surrounded by electrons.

compound

A substance formed by the chemical bonding of two or more different types of atoms.

molecule

A group of two or more atoms chemically bonded together.

metal

A solid, conductive element that is typically malleable and ductile.

characteristics of metal

Properties include high conductivity, malleability, ductility, and luster.

nonmetal

An element that is a poor conductor and lacks metallic properties like malleability.

metalloid

An element with properties intermediate between metals and nonmetals, often used as a semiconductor.