BIOL210 Exam 1

Name the three domains of life.

Archaea, Bacteria, Eukarya

What is the macromolecule that was used for the three domains of life classification?

rRNA (ribosomal)

What are the properties of life?

Order

Sensitivity or response to stimuli

Reproduction, growth and development

Adaption

Regulation and homeostasis

Energy processing

What is homeostasis?

The ability of an organism to maintain a stable internal environment despite external changes.

What is the ordering of living matter? i.e., the biological organization of living matter.

Atoms - molecules - cells - tissues - organs - organ systems - organism - population - community - ecosystem - biosphere

What is the direction of information flow in a cell?

DNA - RNA - Protein

What is an element?

A substance that cannot be broken down into a simpler substance by chemical means. It is defined by the number of protons in its nucleus.

What is an atom?

The smallest unit of matter that retains the properties of an element, consisting of protons, neutrons, and electrons.

How many elements or atoms are there in the universe?

118 known elements

What is an isotope?

Atoms of the same element that have different numbers of neutrons, resulting in different atomic masses.

What is the octet rule?

The principle that atoms tend to bond in such a way that they have eight electrons in their outermost shell, achieving a stable electron configuration.

Can you order the chemical bonds from the strongest to the weakest?

Covalent - ionic - hydrogen - van der waals

What is the difference between a molecule and a compound?

Molecule - two or more atoms bonded together

Compound - molecule made of atoms from at least two different elements

Are all molecules, compounds?

No

Are all compounds, molecules?

Yes

What is a polar covalent bond?

A type of chemical bond where electrons are shared unequally between two atoms, resulting in partial positive and negative charges.

What is electronegativity?

Ability of an atom to attract electrons

What is a hydrogen bond?

A weak attraction between a hydrogen atom bonded to an electronegative atom and another electronegative atom

What is the basis for hydrophilicity and hydrophobicity of compounds?

The basis lies in their polarity and ability to form hydrogen bonds with water. Hydrophilic interact well with water. hydrophobic does not.

What does the pH measure?

Measures concentration of hydrogen ions in a solution, indicating acidity or basicity.

What is the neutral pH?

7

What is the acidic pH?

less than 7

What is the basic pH?

greater than 7

What do organisms use to keep their cellular pH near-neutrall?

Use buffers like bicarbonate to resist changes in pH

How many covalent bonds can a carbon atom make?

4

What is an aliphatic hydrocarbon?

Hydrocarbon chain that is not aromatic (lacks a ring structure)

What is an aromatic hydrocarbon?

Hydrocarbon that contains a ring structure with alternating single and double bounds

What is an isomer?

Compounds with the same molecular formula but different structures or attainments of atoms

What are the different types for isomers?

Structural isomers

Stereoisomers

What is the chemical process by which biological macromolecules are synthesized?

Synthesized through dehydration syntheses, where water is removed to form bonds

What is the chemical process by which boiological macromolecules are broken down?

Broken down through hydrolysis where water is added to break bonds

What are the two types of nucleic acid macromolecules?

DNA

RNA

What are the different kinds of RNA?

mRNA

tRNA

rRNA

miRNA

What is the covalent bond that forms the basis of the sugar-phosphate backbone of the DNA and RNA macromolecules?

Phosphodiester bond

What is a purine?

A type of nitrogenous base with a double-ring structure

What is a pyrimidine?

A type of nitrogenous base with a single-ring structure

What are the purines used in DNA and RNA?

DNA: Adenine (A), Guanine (G)

RNA: Adenine (A), Guanine (G)

What are the pyrimidines used in DNA and RNA?

DNA: Cytosine (C), Thymine (T)

RNA: Cytosine (C), Uracil (U)

What is the sugar molecule present in DNA? RNA?

DNA: Deoxyribose

RNA: Ribose

What is the bond that stabilized the double helical structure of the DNA?

Hydrogen bond

What is chromatin?

Complex of DNA and proteins found in the nucleus, which condense to form chromosomes during cell division

What is a gene?

Segment of DNA that encodes information to produce a functional product, typically a protein or RNA molecule

What is a chromosome?

A structure made of tightly coiled DNA and proteins that carries genetic information

What is the monomer of DNA or RNA called?

Nucleotide

What does it mean to say that the DNA strands in the double helix are antiparallel?

The two DNA strands run in opposite directions (5’ to 3’ or 3’ to 5’)

What is the monomer of proteins called?

Amino acids

What is the covalent bond that connects the amino acids in a protein called?

Peptide bond

What are the four levels or descriptors of protein structure?

Primary structure

Secondary structure

Teritary structure

Quaternary structure

What defines the primary structure of a protein?

The linear sequence of amino acids connected by peptide bonds

What defines the secondary structure of a protein?

The regular, repeating local structures formed through hydrogen bonding between the backbone atoms

What are the two secondary structures common to proteins?

α-helix

β-pleated sheet

What defines the territory structure of a protein?

The 3D folding of the protein, stabilized by various interactions between the R groups

What defines the quaternary structure of a protein?

The interaction and arrangement of multiple polypeptide subunits into a functional protein

What component of an amino acid defines its physical and chemical properties?

The R group (side chain)

What is protein denaturation?

Process by which a protein loses its native structure, usually due to environmental factors like heat or pH changes, causing it to lose its function

What is the covalent bond that connects individual carbohydrate monomers called?

Glycosidic bond

Name the common polysaccharides made by plants?

Starch and cellulose

Name the polysaccharide that is produced by animal cells to store excess glucose reserves.

Glycogen

What are the two forms of starch? And what is the structural difference between them?

Amylose

Amylopectin

What is chitin?

A polysaccharide that provides structural support in the exoskeletons of arthropods and the cell walls of fungi

What is the covalent bond that connects glycerol with fatty acids in triaclyglycerol called?

Ester bonds

What is the structural difference between saturated and unsaturated fatty acids?

Saturated: have no double bonds between carbon atoms, making them straight chains

Unsaturated: have one or more double bonds, causing kinks in the chain

What is the structural difference between cis and trans fatty acids?

Cis: have hydrogen atoms on the same side of the double bond, creating a bend in the chain

Trans: have hydrogen atoms on opposite sides of the double bond, making the chain straighter

What is an essential fatty acid? Example?

Fatty acids the body cannot synthesize and must be obtained from the diet (Omega-3 fatty acids

What are the chemical components of wax?

Waxes are typically long-chain fatty acids linked to long-chain alcohols

What is the salient feature of a phospholipid?

It has a hydrophilic head and hydrophobic tails which makes them ideal for forming cell membranes

What is the key structural feature of steroids?

Four-ring carbon structure

What is the most common steroid molecule in the human body?

Cholesterol

In microscopy, what does magnification mean?

Refers to how much larger an object appears when viewed through a microscope

In microscopy, what does resolution mean?

Ability to distinguish two points as separate entities (how clear and detailed an image is)

What are the three tenets of the united cell theory?

1. All living organisms are made of cells

2. The cell is the basic unit of life

3. All cells come from pre-existing cells

What is the characteristic difference between prokaryotic and eukaryotic cells?

Pro: Lacks a nucleus and membrane-bound organelles

Eu: Has a nucleus and membrane-bound organelles

What cells from the three domains of life belong to prokaryotes?

Bacteria and archaea

Where is the genetic information (DNA) of the bacterial chromosome stored within the cell?

Stored in the nucleotide region (not in a membrane-bound nucleus)

What are the four components of cells that are common to all life?

1. Plasma membrane

2. Cytoplasm

3. Ribosomes

4. Genetic material (DNA)

What is the function of pili in bacteria?

Used for adhesion to surfaces and conjugation (transfer of genetic material)

What is the function of the bacterial flagellum?

Provides motility, allowing bacterium to move toward or away from stimuli

What are the three major cytoskeletal components of eukaryotic cells?

1. Microfilaments

2. Intermediate filaments

3. Microtubules

What is the function of centrosome?

It is the microtubule-organizing center and plays a key role in cell division (mitosis)

What is a lysosome and what is its function in the cell?

Lysosomes are involved in digestion and waste removal, containing enzymes that break down cellular waste, damaged organelles, and pathogens

What is the golgi apparatus and what is its function in the cell?

Processes, sorts and packages proteins and lipids for transport inside or outside the cell

What is the ER and how many types of ER are present in the cell?

A network of membranes involved in protein and lipid synthesis

1. Rough ER: With ribosomes, for protein synthesis

2. Smooth ER: Without ribosomes, for lipid synthesis and detoxification

What are the key functions of the two types of ER?

Rough ER: Synthesizes protein and folds them

Smooth ER: Synthesizes lipids, metabolizes carbohydrates, and detoxified drugs and poisons

What is the structure and function of the mitochondria?

Mitochondria have a double membrane, with the inner membrane forming folds called cristae. They are the powerhousesof the cell, producing ATP through cellular respiration.

What is the structure and function of the chloroplast?

Chloroplasts have a double membrane and contain the pigment chlorophyll, They are responsible for photosynthesis in plant cells

What is the function of peroxisomes?

Peroxisomes contain enzymes for breaking down fatty acids and detoxifying harmful substances like hydrogen peroxide.

What is the function of cell nucleus?

The nucleus houses the DNA and is involved in gene expression and cell division

What is the function of nucleolus?

Involved in ribosome synthesis and the assembly of rRNA

What are the cellular organelles that contains DNA?

1. Nucleus

2. Mitochondria

3. Chloroplasts (in plants)

What is the primary sit of cellular glycoproteins and glycolipids?

Golgi apparatus

What is cytoplasm?

Jelly-like substance inside the cell that contains all the organelles and is the sit for many biochemical reactions

What is the cytosol?

The liquid portion of the cytoplasm, excluding organelles that contain water, salts and proteins

How many membranes does the mitochondria have?

Two; inner and outer

What is the interior of the mitochondria called?

The matrix

What is a centrosome?

An organizing center for microtubules and is involved in cell division. It contains centrioles which organize the mitotic spindle during mitosis

What are the animal cell organelles that plant cells don’t have?

1. Lysosomes

2. Centrosomes

3. Cilia/Flagella

What are the plant cell organelles that animal cells don’t have?

1. Cell Wall

2. Chloroplasts

3. Central vacuole

4. Plasmodesmata (channels for communication

What is endosymbiosis? And what are the endosymbiotic organelles in the plant and animal cells?

• A theory suggesting that mitochondria and chloroplasts were once free-living prokaryotes that were engulfed by a host cell, forming a symbiotic relationship.

• Endosymbiotic organelles in plant and animal cells: Mitochondria (found in all eukaryotes) and Chloroplasts (found in plant cells).

What is the endomembrane system?

System of interconnected membranes involve din the synthesis, modification and transport of lipids and proteins

What are the components of the endomembrane system?

1. Nuclear envelope

2. Endoplasmic reticulum (ER)

3. Golgi apparatus

4. Lysosomes

5. Vesicles

6. Plasma membrane