Science Basics Flashcards

Question

Which of the following statements about isotopes is true? A. They have different number of protons B. They have the same number of neutrons C. They have different numbers of neutrons D. They have different atomic numbers

Answer 1

C. They have different number of neutrons ## Footnote Isotopes have different numbers of neutrons.

Answer 2

B. Molecule ## Footnote A molecule consists of bonded atoms

Answer 3

B. Decomposition ## Footnote Decomposition breaks molecules down.

Answer 4

B. Build cell membranes and store energy ## Footnote Lipids store energy and form membranes

Answer 5

C. Phospholidpids ## Footnote Phospholipids are the main component of membranes

Answer 6

C. Carbohydrates ## Footnote Carbohydrates are the body’s primary energy source.

Answer 7

C. Amino acids ## Footnote Amino acids are protein monomers.

Answer 8

C. Peptide bond ## Footnote Peptide bonds link amino acids

Answer 9

B. Speed up chemical reactions ## Footnote Enzymes catalyse reactions

Answer 10

C. Starch ## Footnote Starch is a polysaccharide.

Answer 11

B. DNA ## Footnote DNA contains thymine.

Answer 12

B. Carry out protein synthesis ## Footnote RNA assists in protein synthesis

Answer 13

B. Mechanical energy ## Footnote Mechanical energy moves body parts

Answer 14

A. Electrons are shared equally ## Footnote Non-polar bonds share electrons equally

Answer 15

B. Store and transfer energy ## Footnote ATP stores and transfer energy

Answer 16

C. Proteins ## Footnote Proteins are organic

Answer 17

B. Dehydration synthesis ## Footnote Dehydration synthesis removes water ton bond sugars

Answer 18

B. Secondary ## Footnote Alpha helices and beta sheets are secondary structures.

Answer 19

B. Collagen ## Footnote Collagen provides structural support.

Answer 20

B. Protein ## Footnote Hemoglobin, a protein, carries oxygen.

Answer 21

C. Regulate body functions (hormones) ## Footnote Steroids regulate functions as hormones.

Answer 22

A. ATP ## Footnote ATP is an nucelotide

Answer 23

B. They denature and lose function. ## Footnote Denaturation disrupts protein function

Answer 24

C. Nitrogenous base ## Footnote The nitrogenous base carries genetic information.

Answer 25

a – Hydrolysis breaks bonds by adding water.

Answer 26

B. Atoms of the same element with different numbers of neutrons. ## Footnote Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

Answer 27

A. It is an isotope that emits radiation due to an unstable nucleus. ## Footnote A radioisotope is an isotope with an unstable nucleus that emits radiation in the form of alpha, beta, or gamma rays in order to reach a more stable state. These are commonly used in medical treatments, such as in radiation therapy or imaging.

Answer 28

A. A non-polar covalent bond occurs when electrons are equally shared, while a polar covalent bond occurs when electrons are unequally shared. ## Footnote In non-polar covalent bonds, electrons are shared equally between two atoms, typically when the atoms have similar electro negativities (like in a bond between two identical atoms, e.g., O₂ or N₂). In polar covalent bonds, electrons are shared unequally because one atom has a higher electronegativity than the other, creating a dipole (partial positive and negative charges) within the molecule (e.g., in H₂O).

Answer 29

B. A cation is a positively charged ion, while an anion is a negatively charged ion. ## Footnote A cation is an ion with a positive charge, formed when an atom loses electrons. An anion is an ion with a negative charge, formed when an atom gains electrons.

Answer 30

B. Two or more reactants combine to form a single product ## Footnote A synthesis reaction (also called a combination reaction) occurs when two or more substances combine to form a single, more complex product. The general form is: A + B → AB

Answer 31

B. A single compound breaks down into two or more simpler substances. ## Footnote A decomposition reaction involves the breakdown of a single compound into two or more simpler products. The general form is: AB → A + B

Answer 32

C. Ions are exchanged between two compounds to form new products. ## Footnote An exchange reaction (also called a double displacement or metathesis reaction) occurs when the ions of two compounds are exchanged to form new compounds. The general form is: AB + CD → AD + CB

Answer 33

D. The colour of the reactants ## Footnote Temperature: Increases the rate of reaction because it causes molecules to move faster and collide more frequently. Concentration of reactants: A higher concentration of reactants increases the likelihood of collisions between molecules, thus speeding up the reaction. Surface area of reactants: A larger surface area allows more particles to interact, increasing the rate of reaction.

Answer 34

B. Water (H₂O) ## Footnote Inorganic compounds are typically compounds that do not contain both carbon and hydrogen atoms together. Water (H₂O) is a classic example of an inorganic compound because it does not contain carbon. Glucose is an organic compound, as it contains both carbon and hydrogen atoms. Protein is also an organic compound, as proteins are made of amino acids, which contain carbon, hydrogen, nitrogen, and oxygen. DNA is an organic compound because it contains carbon, hydrogen, nitrogen, and phosphorus atoms.

Answer 35

C. Glucose (C₆H₁₂O₆) ## Footnote Organic compounds are generally characterized by the presence of carbon-hydrogen (C-H) bonds. Glucose (C₆H₁₂O₆) is an organic compound because it contains carbon and hydrogen atoms bonded together. - Sodium chloride is an inorganic compound as it consists of sodium and chlorine, with no carbon-hydrogen bonds. - Carbon dioxide is an inorganic compound because it contains carbon but no hydrogen atoms. - Ammonia is also an inorganic compound, as it consists of nitrogen and hydrogen without any carbon atoms.

Answer 36

B. To provide energy for cellular functions ## Footnote Carbohydrates are a major source of energy for the body. They are broken down into glucose, which is used by cells for energy. This is the primary function of carbohydrates in the body. Carbohydrates include sugars, starches, and fibres and are essential for energy production, especially for the brain and muscles during exercise.

Answer 37

C. Glucose ## Footnote Monosaccharides are the simplest form of carbohydrates. Includes simple sugars like glucose, fructose, and galactose, which are key energy sources for the body.

Answer 38

B. Maltose ## Footnote A disaccharide is a carbohydrate made up of two monosaccharide units bonded together. Maltose is a disaccharide composed of two glucose molecules. It is commonly found in malt and is produced during the digestion of starch. Disaccharides include sugars like sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose).

Answer 39

C. Glycogen ## Footnote Polysaccharides are complex carbohydrates made up of long chains of monosaccharide units. Glycogen is a polysaccharide that serves as a form of energy storage in animals, particularly in the liver and muscles. Other examples of polysaccharides include starch (energy storage in plants) and cellulose (a structural component in plant cell walls). Polysaccharides serve primarily as energy storage or structural components in living organisms.

Answer 40

B. To provide a source of long-term energy and support cell membrane structure ## Footnote Lipids serve several important functions in the body, including providing a long-term source of energy, forming the structure of cell membranes (phospholipids), and aiding in the absorption of fat-soluble vitamins (A, D, E, K). They are also involved in hormone production. Lipids include fats, oils, phospholipids, and steroids. They are essential for energy storage, cell membrane integrity, insulation, and hormone regulation.

Answer 41

B. They are made up of three fatty acids attached to a glycerol molecule and are the main form of fat storage in the body. ## Footnote Triglycerides are a type of lipid composed of three fatty acids bonded to a single glycerol molecule. They are the body's primary form of fat storage and are stored in adipose tissue. When the body needs energy, triglycerides can be broken down to provide it. Triglycerides are essential for long-term energy storage, insulation, and protection of organs. Known as fast when solid, oils when liquid.

Answer 42

C. To form the basic structure of cell membranes ## Footnote Phospholipids are a major component of cell membranes. They consist of a hydrophilic (water-attracting) "head" and two hydrophobic (water-repelling) "tails," which allows them to form the bilayer structure of cell membranes. This structure is essential for maintaining the integrity and function of cells.

Answer 43

C. To regulate metabolic processes and serve as precursors to hormones ## Footnote Steroids are a type of lipid that include molecules like cholesterol and hormones such as testosterone, estrogen, and corticosteroids. They are important for regulating various physiological processes, including metabolism, immune response, and reproductive functions. Cholesterol, a steroid, is also a precursor to these hormones. Steroids play a crucial role in many biological functions, including acting as hormones that regulate inflammation, immune response, and reproductive processes. Cholesterol, the most well-known steroid, is essential for the production of these hormones.

Answer 44

B. To regulate the composition and fluidity of cell membranes ## Footnote Cholesterol is essential for proper cell function, the synthesis of steroid hormones (like cortisol and sex hormones), and the production of bile acids, which help with digestion.

Answer 45

B. To regulate the body's metabolism and act as enzymes ## Footnote One of their key roles is acting as enzymes, which are catalysts that speed up biochemical reactions in the body. Proteins also contribute to metabolic regulation, immune function, and tissue repair. Proteins are made up of amino acids and are essential for almost every bodily function, from building tissues and muscles to carrying out biochemical reactions as enzymes.

Answer 46

B. Globular proteins are soluble in water, while fibrous proteins are insoluble. ## Footnote Globular proteins are typically soluble in water and have a more compact, spherical shape. They are involved in various functions, such as enzymes, antibodies, and transport proteins (e.g., hemoglobin). Their solubility allows them to function in the aqueous environments of cells. Fibrous proteins, on the other hand, are insoluble in water and have elongated, thread-like structures. They provide structural support in cells and tissues (e.g., collagen, keratin). In summary, globular proteins are functional and water-soluble, whereas fibrous proteins are structural and insoluble.

Answer 47

B. To speed up chemical reactions without being consumed in the process ## Footnote Enzymes are biological catalysts that accelerate the rate of chemical reactions in the body. They work by lowering the activation energy required for a reaction to occur, allowing metabolic processes to happen more efficiently. Enzymes are crucial in digestion, metabolism, and various other physiological processes. They help break down nutrients, synthesise molecules, and regulate chemical pathways in cells.

Answer 48

B. DNA contains the sugar deoxyribose, while RNA contains the sugar ribose. ## Footnote One of the primary differences between DNA (Deoxyribonucleic acid) and RNA (Ribonucleic acid) is the type of sugar they contain. DNA contains deoxyribose, while RNA contains ribose. This difference is important because it affects the structure and stability of each molecule. DNA stores genetic information in the form of a double helix, while RNA plays a critical role in translating that information into proteins.

Answer 49

A. mRNA carries genetic information from the nucleus to the ribosomes for protein synthesis. ## Footnote mRNA is a type of RNA that carries genetic instructions from DNA in the nucleus to the ribosomes, where protein synthesis occurs. It is synthesised in the nucleus and then moves to the cytoplasm.

Answer 50

B. Adenine pairs with Thymine, and Cytosine pairs with Guanine. ## Footnote In DNA, the nitrogenous bases pair in a specific way: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). This base-pairing rule is crucial for the double helix structure of DNA. "At The Gold Coast"

Answer 51

B. Adenine pairs with Uracil, and Cytosine pairs with Guanine ## Footnote In RNA, the base pairing is similar to DNA, but with one key difference. Adenine (A) pairs with uracil (U) in RNA (instead of thymine in DNA), and cytosine (C) pairs with guanine (G). "All Undies Get Cleaned"

Answer 52

B. To store and transmit genetic information Rationale: The primary function of DNA is to store and transmit genetic information. DNA is organised into genes, which are responsible for encoding the information needed to make proteins, but DNA itself does not directly participate in protein synthesis.

Answer 53

C. To replicate itself during cell division ## Footnote DNA also plays a critical role in replicating itself during cell division. This ensures that each new cell receives an identical copy of the genetic material. It is essential for growth, repair, and reproduction of cells.

Answer 54

C. It forms the structure of ribosomes and facilitates protein synthesis. ## Footnote rRNA is a component of ribosomes, where it helps with the synthesis of proteins. It serves both as a structural component and as a facilitator of the biochemical processes involved in protein synthesis.

Answer 55

B. ATP acts as an energy source by transferring high-energy phosphate bonds to enzymes during metabolic reactions, powering processes such as active transport and muscle contraction. Rationale: ATP (Adenosine Triphosphate) is a molecule that stores and provides energy for cellular functions. It contains high-energy phosphate bonds, and when these bonds are broken (in the process of hydrolysis), energy is released. This energy is used to power various cellular processes such as active transport, muscle contraction, protein synthesis, and cell division. The energy released from ATP is transferred to enzymes or other molecules during metabolic reactions to drive these processes.

Science Basics Flashcards

(80 cards)