Biochem ESHS 9th Grade

What are nucleic acids composed of?

Nucleic acids are composed of nucleotides.

What is the structure of RNA?

RNA consists of ribose sugar, a phosphate group, and a nitrogen base.

What does mRNA stand for?

Messenger RNA, carry the genetic information needed to make proteins

What is the role of tRNA?

Transfer RNA transfers amino acids to the ribosome.

What is the function of rRNA?

Ribosomal RNA serves as a structural component of ribosomes. (link amino acids together)

What is DNA?

Deoxyribonucleic acid, a material consisting of two polynucleotide chains.

What sugar is found in DNA?

Deoxyribose.

What are the four nitrogen bases in DNA?

Adenine, Thymine, Cytosine, Guanine.

What is Chargaff's Rule?

The amount of adenine equals thymine, and the amount of cytosine equals guanine.

Describe the double helix structure of DNA.

DNA has a double helical structure formed by the binding of complementary bases.

What are the key functions of proteins?

Proteins help maintain cell shape, act as enzymes, and carry messages.

What are amino acids?

The monomers that make up proteins.

What causes denaturation in proteins?

Denaturation occurs when proteins change shape due to external forces like pH and temperature.

How many levels of protein structure are there?

There are four levels of protein structure: primary, secondary, tertiary, and quaternary.

What is the primary structure of proteins?

The sequence of amino acids in its polypeptide chain.

What is the secondary structure of proteins?

Folding structures within a polypeptide, stabilized by chemical bonds.

What characterizes the tertiary structure of proteins?

The 3-D shape of a protein, controlling its basic function.

What is a quaternary structure?

A structure formed by multiple polypeptide chains working as a single complex.

What are steroids?

Lipids with a ring structure that function in growth and energy metabolism.

What is a triglyceride?

A lipid formed by combining glycerol with three fatty acids.

What distinguishes saturated fatty acids from unsaturated fatty acids?

Saturated fatty acids have no double bonds, while unsaturated fatty acids do.

What is the function of phospholipids?

Phospholipids form the cell membrane of living cells.

What does 'hydrophilic' mean?

Attracted to water.

What does 'hydrophobic' mean?

Repelled by water.

What is a carbohydrate?

A compound that includes sugars, fibers, and starches.

What are monosaccharides?

The simplest form of carbohydrates, consisting of single sugar molecules.

What is a disaccharide?

A carbohydrate composed of two monosaccharide molecules.

What is a polysaccharide?

A carbohydrate that consists of many monosaccharide units.

What is the role of carbohydrates in living things?

They provide energy and serve as structural components.

What are proteins?

Large molecules made up of amino acids that perform a variety of functions in organisms.

What is the mass number of an atom?

The total number of protons and neutrons in an atom.

What is the atomic number of an element?

The number of protons in the nucleus of an atom.

What is matter?

Anything that has mass and occupies space.

What are isotopes?

Atoms of the same element with the same number of protons but different numbers of neutrons.

What is an ionic bond?

A bond formed by the transfer of electrons from one atom to another.

What is a covalent bond?

A bond formed when atoms share electrons.

What is a hydrogen bond?

A weak bond occurring between a hydrogen atom and another electronegative atom.

What is cohesion?

The tendency of molecules to stick together, as seen in water.

What is adhesion?

The attraction between water molecules and different substances.

What is pH?

A measure of the acidity or alkalinity of a solution.

What are buffers?

Substances that help resist changes in pH.

What is an enzyme?

A protein that acts as a catalyst, speeding up chemical reactions.

What is activation energy?

The energy required to start a chemical reaction.

What is the function of enzymes?

To lower the activation energy of a chemical reaction.

What factors affect enzyme activity?

Temperature, pH levels, enzyme concentration, substrate concentration, and the presence of inhibitors and activators.

What is the role of water in living organisms?

Water is essential for biochemical reactions, helps regulate temperature, and serves as a solvent.

What does it mean when a solution is labeled as acidic?

It has a higher concentration of hydronium ions than pure water.

What happens in a neutral solution?

The concentration of hydrogen ions and hydroxide ions is equal.

What is an example of a saturated fat?

Butter is an example of a saturated fat.

What creates the surface tension of water?

Cohesive forces between water molecules.

How does ice differ from liquid water?

Ice is less dense than liquid water and floats on it.

What are solutes?

Substances that dissolve in a solvent.

What is a solvent?

The liquid in which solutes dissolve.

What does soluble mean?

A substance that can dissolve in a liquid.

What does insoluble mean?

A substance that cannot dissolve in a liquid.

What is the high heat capacity of water?

Water can absorb a lot of heat energy before its temperature increases.

What impact do temperature and pH have on enzyme activity?

They significantly influence the rate and efficiency of enzymatic reactions.

What is the significance of water being a polar molecule?

It affects its solvent properties and interactions with other molecules.

What is the function of the nitrogenous base in nucleotides?

It determines the genetic code in DNA and RNA.

What are the two main types of nucleic acids?

DNA and RNA.

What role do enzymes play in metabolic processes?

They catalyze biochemical reactions essential for metabolism.

What is an example of a polysaccharide?

Starch, cellulose, and glycogen are examples of polysaccharides.

What are macromolecules?

Large molecules made up of smaller units called monomers.

What is the structure of a nucleotide?

Consists of a pentose sugar, a phosphate group, and a nitrogen base.

What are fatty acids?

Building blocks of lipids, composed of chains of carbon atoms.

What is the significance of hydrogen bonding in water?

It contributes to water's unique properties, such as cohesion and adhesion.

What is the definition of an anabolic reaction?

A reaction that builds larger molecules from smaller ones.

What is the definition of a catabolic reaction?

A reaction that breaks down larger molecules into smaller units.

What is a primary component of cell membranes?

Phospholipids are the main component of cell membranes.

What does denaturation refer to in the context of proteins?

The alteration of a protein's structure due to external factors such as pH or temperature.

What is the function of antibodies in the body?

They bind to specific foreign substances to help defend against pathogens.

What is the structure of a triglyceride?

Composed of one glycerol molecule and three fatty acid molecules.

What is the basic building block of carbohydrates?

Monosaccharides are the building blocks of carbohydrates.

What do we call the process of water splitting into its ions?

The dissociation of water into hydrogen and hydroxide ions.

How do phospholipids arrange themselves in water?

They form a bilayer with hydrophilic heads facing outwards and hydrophobic tails inward.

What is an example of a structural protein?

Keratin, found in hair and nails.

What is the characteristic of an ionic bond?

It involves the transfer of electrons and forms charged ions.

What do we mean by nonpolar covalent bonds?

Covalent bonds where electrons are shared equally between atoms.

What is the importance of water being a universal solvent?

It allows for the dissolution of many substances essential for biological reactions.

How does temperature affect enzyme activity?

Increasing temperature generally speeds up enzyme activity until denaturation occurs.

What is a common property of lipids?

They are generally hydrophobic and insoluble in water.

How does ice floating on water benefit aquatic life?

It insulates the water below, maintaining a stable environment for aquatic organisms.

What is an example of a sugar that functions as an energy source for cells?

Glucose is a primary energy source for cells.

What type of reaction releases energy?

Catabolic reactions release energy by breaking down molecules.

What is the primary role of glucose in living organisms?

To provide energy for cellular processes.

What role do buffers play in biological systems?

They help maintain stable pH levels in biological fluids.

What is the significance of a high heat of vaporization in water?

It allows organisms to regulate temperature through evaporative cooling.

How do enzymes and substrates interact?

Enzymes bind specifically to substrates at their active sites, facilitating chemical reactions.

What happens to enzymes at extreme pH levels?

They typically denature and lose their functional shape.