Review #1 Exam

What is false about the generation of life?

Some cells are spontaneously generated from material in the environment.

What is the purpose of the control group in experimental design?

It serves as a comparison to the experimental group that receives treatment.

In a solution with water molecules surrounding a solute, how do the water molecules orient themselves?

Oxygen molecules face the positively charged solute, and hydrogen molecules face the negatively charged solute.

Which chemical bond is the weakest?

The bond between oxygen and hydrogen in neighboring water molecules.

What is true about bond formation?

Bonds are formed to fill and stabilize the valence orbital of atoms.

What is a peptide bond?

A bond between the c-terminus and n-terminus of amino acids.

Which level of protein folding does not involve hydrogen bonding?

Primary level, which only has peptide bonds.

What is the effect of an enzyme on a reaction compared to an uncatalyzed reaction?

The catalyzed reaction will have the same ∆G.

What type of inhibitor is Ibuprofen?

Competitive inhibitor.

What modification is needed to change DNA nucleotide to an RNA nucleotide?

Add a 2' OH group.

If a DNA sample contains 31% thymine (T), what percentage of guanine (G) will be present?

19%.

What is TRUE about joining nucleotide monomers to nucleic acids?

A covalent bond forms between the sugar of one nucleotide and the phosphate of a second.

What pyrimidines are found in RNA and DNA?

Cytosine, uracil, and thymine.

Why do researchers believe RNA was the first hereditary molecule?

RNA can carry information and catalyze chemical reactions.

Why can humans digest glucose from plants but not from plant cell walls?

Humans have enzymes for α-glycosidic linkages of starch, not β-glycosidic linkages of cellulose.

How do α and β forms of glucose differ?

Their ring structures differ in the location of a hydroxyl group.

How is membrane permeability to glucose affected by increased unsaturated phospholipids?

Permeability increases.

What allows phospholipids to form a cell membrane?

Polar heads orient towards water, and non-polar tails face inward.

What roles does cholesterol play in the body?

Starting material for steroids, membrane permeability, and fluidity.

What organelle is responsible for protein synthesis?

Ribosome.

Which organelle creates ATP?

Mitochondria.

What structure provides protection and support in plant cells?

Cell wall.

What is the function of the endomembrane system?

Sends instructions for protein synthesis and processes lipids.

What is the role of lysosomes?

Digestion and recycling components.

What provides structural support and movement in eukaryotic cells?

Cytoskeleton.

What function does the peroxisome serve?

Involves oxidation reactions.

What surrounds all cells?

Plasma membrane.

Fill in the blank: Proteins are made up of long chains of __________.

amino acids.

Fill in the blank: The sequence of amino acids in a protein is called its __________.

primary structure.

Fill in the blank: __________ bonds are responsible for the secondary structure of proteins.

Hydrogen.

Fill in the blank: The three-dimensional shape of a protein is crucial for its __________.

function.

Fill in the blank: Proteins that speed up chemical reactions in the body are called __________.

enzymes.

Fill in the blank: Hemoglobin is a protein that carries __________ in the blood.

oxygen.

Fill in the blank: A protein's __________ structure refers to its overall three-dimensional shape.

tertiary.

Fill in the blank: Proteins can be denatured by changes in __________ or pH.

temperature.

Fill in the blank: The __________ structure of protein refers to the arrangement of multiple polypeptide chains.

quaternary.

What are carbohydrates primarily composed of?

Carbon, hydrogen, and oxygen.

What is the main function of carbohydrates in the body?

To serve as a primary energy source.

What is a disaccharide?

A carbohydrate formed by the combination of two monosaccharides.

What are lipids mainly composed of?

Fatty acids and glycerol.

What is the primary function of lipids?

To store energy and form cell membranes.

What are the types of lipids?

Fats, oils, waxes, phospholipids, and steroids.

What distinguishes saturated fats from unsaturated fats?

Saturated fats have no double bonds between carbon atoms, while unsaturated fats have one or more.

What is the role of phospholipids in cells?

To make up the cell membrane.

Why are lipids important for insulation?

They help maintain body temperature by providing insulation.

What is the function of the nucleus?

It stores genetic information and coordinates cell activities.

What is the role of the endoplasmic reticulum (ER)?

To synthesize proteins and lipids; includes rough and smooth ER.

What is the function of the Golgi apparatus?

To modify, sort, and package proteins and lipids for secretion or delivery.

What do mitochondria do?

Generate ATP through cellular respiration, providing energy for the cell.

What is the role of lysosomes?

To digest and recycle cellular waste and damaged organelles.

What are ribosomes responsible for?

Protein synthesis by translating messenger RNA (mRNA).

What do chloroplasts do?

Conduct photosynthesis in plant cells by converting solar energy into chemical energy.

What is the function of the plasma membrane?

To control the movement of substances in and out of the cell.

What does the cytoskeleton provide?

Structural support and shape to the cell; aids in movement.

What organelle is known as the 'powerhouse' of the cell?

Mitochondria, as they produce energy in the form of ATP.

What are monosaccharides?

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

Give an example of a monosaccharide.

Glucose, fructose, and galactose are examples of monosaccharides.

What is the general formula for monosaccharides?

The general formula is (CH2O)n, where n is the number of carbon atoms.

What are polysaccharides?

Carbohydrates composed of long chains of monosaccharide units linked by glycosidic bonds.

Give an example of a polysaccharide.

Starch, glycogen, and cellulose are examples of polysaccharides.

What is the primary function of starch in plants?

Starch serves as a storage form of energy.

What is the major structural polysaccharide in plants?

Cellulose is the major structural polysaccharide in plant cell walls.

How are polysaccharides formed from monosaccharides?

Polysaccharides are formed through a dehydration reaction that links monosaccharides.

What is glycogen, and where is it stored in the human body?

Glycogen is a polysaccharide that stores energy, primarily in the liver and muscles.

What distinguishes dietary fiber from starch?

Dietary fiber consists mainly of cellulose, which cannot be digested by humans.