Biology Assessment #1

Question 1

Macromolecules

Answer 1

Large complex molecules essential for life.

Question 2

What are the four main types of macromolecules?

Answer 2

Carbohydrates, Proteins, Lipids, and Nucleic Acids

Question 3

What do carbohydrates do?

Answer 3

Provide energy

Question 4

What do proteins do?

Answer 4

Perform a variety of functions including catalyzing reactions (enzymes), signaling, and structural support

Question 5

What do lipids do?

Answer 5

Store energy and make up cell membranes

Question 6

What do nucleic acids do?

Answer 6

Store and transmit genetic information (DNA and RNA)

Question 7

What is a monomer?

Answer 7

A small, basic molecular unit that can bind chemically to other monomers to form a larger structure. It is like a single “building block” that can join together with others to form complex molecules.

Question 8

What is a polymer?

Answer 8

A large molecule made up of repeating units of monomers linked together through chemical bonds. Polymers are long chains or structures formed from these smaller monomers, and they can be natural or synthetic.

Question 9

Monomers of Carbohydrates

Answer 9

Monosaccharides (e.g., glucose)

Question 10

Polymers of Carbohydrates

Answer 10

Polysaccharides (e.g., starch, glycogen, cellulose)

Question 11

Functions of Carbohydrates

Answer 11

Primary energy source (glucose used in cellular respiration)
Structural support in plants (cellulose)

Question 12

Monomers of Proteins

Answer 12

Amino acids (20 different kinds)

Question 13

Polymers of Proteins

Answer 13

Polypeptides, which fold into complex 3D structures to form functional proteins

Question 14

Functions of Proteins

Answer 14

Enzymes: Proteins that catalyze biochemical reactions by lowering the activation energy
Structural support (e.g., collagen), transport (e.g., hemoglobin), defense (e.g., antibodies)

Question 15

Monomers of Lipids

Answer 15

Fatty acids and glycerol

Question 16

Polymers of Lipids

Answer 16

Triglycerides, phospholipids (key component of cell membranes), and steroids

Question 17

Functions of Lipids

Answer 17

Long-term energy storage.
Insulation and protection.
Making up cell membranes (phospholipids).

Question 18

Monomers of Nucleic Acids

Answer 18

Nucleotides (sugar, phosphate group, nitrogenous base)

Question 19

Polymers of Nucleic Acids

Answer 19

DNA (stores genetic info) and RNA (transmits genetic info and helps in protein synthesis)

Question 20

Enzymes

Answer 20

Proteins that speed up chemical reactions.

Question 21

Enzyme mechanism

Answer 21

Works by lowering the activation energy of a reaction, making it easier for reactions to occur.

Question 22

Active Site

Answer 22

The part of the enzyme where the substrate binds and the reaction occurs.

Question 23

Enzyme-Substrate Complex

Answer 23

The enzyme binds to the substrate, facilitating the reaction, then releases the product.

Question 24

Enzyme Specificity

Answer 24

Each enzyme is specific to a particular substrate due to the shape of its active site.

Question 25

Factors Affecting Enzyme Activity

Answer 25

Temperature: Too high or too low temperatures can denature the enzyme, altering its shape and function. pH: Each enzyme works best at a specific pH; deviation can denature the enzyme. Concentration: Higher enzyme or substrate concentration increases reaction rate until saturation.

Question 26

Key processes of Enzymes

Answer 26

Dehydration Synthesis: Enzymes help build larger molecules (polymers) by removing water. Hydrolysis: Enzymes break down polymers into monomers by adding water (e.g., during digestion).

Question 27

Denature

Answer 27

When an enzyme loses its specific three-dimensional structure, rendering it unable to perform its biological function. Enzymes are proteins, and their function depends on their specific shape, particularly the shape of the active site where the substrate binds. When an enzyme is denatured, its structure is altered, which typically results in the loss of its ability to bind to substrates and catalyze reactions.

Question 28

Types of ecology models

Answer 28

Pyramids, Webs, Chains

Question 29

Food Chain

Answer 29

A linear sequence showing how energy and nutrients flow from one organism to another.

Question 30

Levels of a food chain

Answer 30

Producers, Primary Consumers, Secondary Consumers, Tertiary Consumers

Question 31

Food Web

Answer 31

A complex network of interconnected food chains that show how energy flows through an ecosystem.

Question 32

Why are food webs important?

Answer 32

Represents the diverse feeding relationships in an ecosystem, showing how different species are interdependent.

Question 33

Energy Pyramid

Answer 33

A graphical representation of energy flow in an ecosystem.

Question 34

Trophic levels

Answer 34

Producers (base with the most energy) → Primary Consumers → Secondary Consumers → Tertiary Consumers (top with the least energy).

Question 35

Energy Transfer (between trophic levels)

Answer 35

Only about 10% of the energy is transferred from one level to the next; the rest is lost as heat.

Question 36

Importance of Nitrogen

Answer 36

Nitrogen is a critical component of amino acids (proteins), nucleotides (nucleic acids), and chlorophyll (in plants).

Question 37

Where does Nitrogen come from?

Answer 37

Nitrogen makes up 78% of Earth's atmosphere, but most organisms cannot use atmospheric nitrogen (N₂) directly.

Question 38

What is the Nitrogen Cycle?

Answer 38

Nitrogen Fixation, Nitrification, Assimilation, Ammonification, Denitrification

Question 39

Nitrogen Fixation

Answer 39

Nitrogen-fixing bacteria in soil and plant root nodules (legumes) convert atmospheric nitrogen (N₂) into ammonia (NH₃), which can be used by plants.

Question 40

Nitrification

Answer 40

Soil bacteria convert ammonia into nitrites (NO₂⁻) and then into nitrates (NO₃⁻), which plants absorb through their roots.

Question 41

Assimilation

Answer 41

Plants take up nitrates and ammonia from the soil and use them to make proteins and other nitrogen-containing compounds.

Question 42

Ammonification

Answer 42

Decomposers (bacteria and fungi) break down dead organisms and waste, converting organic nitrogen back into ammonia, which can re-enter the soil.

Question 43

Dentrification

Answer 43

Denitrifying bacteria convert nitrates back into nitrogen gas (N₂), releasing it back into the atmosphere, completing the nitrogen cycle.

Question 44

How plants get Nitrogen

Answer 44

Absorption: Plants absorb nitrogen from the soil primarily in the form of nitrates (NO₃⁻) and ammonium (NH₄⁺). Symbiotic Relationships: Some plants (especially legumes) form symbiotic relationships with nitrogen-fixing bacteria that live in their root nodules, directly receiving usable nitrogen.