Unit 1 Biochem

Recommended use: Test mode, multiple choice only or flashcards

What 3 states does matter exist in?

solid, liquid, gas

What are the six main elements found in all living things?

carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur

Which element is the most abundant in living things?

carbon

What element makes up the majority of earth’s atmospheres?

nitrogen

What three components make up an atom?

protons, neutrons, electrons

What are trace elements?

elements that are required by an organism but only in minute quantities (ex. iron)

What are isotopes?

atoms of the same element but have different number of neutrons

What is half-life of isotopes?

the amount of time it takes for half a sample of radioactive isotopes to decay into more stable isotopes

A compound is made of how many elements bonded together?

two or more

What are the two types of chemical bonds?`

ionic and covalent

What are ionic bonds?

these bonds are formed when atoms transfer electrons to one another and become ions

What are covalent bonds?

these bonds are formed when atoms share electrons with other atoms

What are ionic compounds also known as?

salts

What are ionic compounds formed with?

positively and negatively charged ions

What is one trait of ionic compounds?

dissociate in water/dissolves in water

What are covalent bonded compounds also called?

molecules

Covalent bonds (do/do not) dissociate in water

do not

What is required to break covalent bonds?

chemical reactions

What are two classifications of covalent compounds (molecules)?

polar or nonpolar

What is a nonpolar molecule?

there is no partial positive or negative region on the molecule because atoms share electrons equally

What is a polar molecule?

there is a partial positive and negative region on the molecule because atoms are not shared equally

What does “like dissolves like” refer to?

polar substances(and charged substances, such as ions) like to associate with other polar substances, while nonpolar substances like to associate with other nonpolar substances.

Nonpolar molecules are (hydrophobic/hydrophilic).

hydrophobic

Polar molecules and ions are (hydrophobic/hydrophilic).

hydrophilic

A molecule’s shape determines its _______.

function

Hydrogen bonds are possible when hydrogen is bonded to ______, ______, and ______.

Fluorine, Oxygen, Nitrogen

Hydrogen bonds are (weak/strong)

weak, but many can be collectively strong

What is cohesion?

a property of water — the ability of water molecules to “cling” to each other due to hydrogen bonding

• ex. Water forming droplets

What is adhesion?

a property of water — ability of water molecules to “cling” to other polar surfaces due to hydrogen bonding

• ex. Water drops sticking to glass

What is capillary action?

water’s ability to “climb” narrow spaces

Why does water form droplets?

surface tension; it is the force created from the molecules at the surface of a liquid being attracted to the molecules below the surface

How do organisms maintain normal internal temperature?

organisms are made of mostly water, which absorbs lots of thermal energy without a great change in temperature

How does sweat work?

essentially evaporative cooling in animals; animal’s body heat is used to evaporate the water

Why does ice float?

due to hydrogen bonds, water expands when it freezes

Why is water considered the “universal solvent”?

it has high polarity, which is able to dissolve many different substances

What is the pH value of a neutral solution?

7

What is the pH value of an acidic solution?

<7

What is the pH of a basic solution?

>7

Where is the energy in ATP stored?

in between the phosphates

A greater H+ concentration in the solution means:

lower pH value (and vice versa)

Organic compounds contain which element?

carbon

How many valence electrons does carbon have?

4

What are huge molecules also called?

macromolecules

How are monomers joined to make polymers?

dehydration synthesis

What is dehydration synthesis?

when water is pulled out in a reaction to connect monomers

What reaction is used to break down polymers into monomers?

Hydrolysis

What are functional groups?

a cluster of atoms in a compound that determines how it reacts, behaves, and interacts physically

What is hydrolysis?

uses water to separate macromolecules (polymers)

Anything with lots of protein needs lots of this element:

nitrogen

How many calories is needed to raise 1 mL of water up 1°C?

1 calorie

What do enzymes do?

help carry out chemical reactions, including dehydration synthesis and hydrolysis reactions

What are enzymes also called?

catalysts

What are the four classes of macromolecules?

carbohydrates, lipids, nucleic acids, and proteins

What are the monomers of carbohydrates called?

monosaccharides

What is a disaccharide?

it contains two monosaccharides bonded together by dehydration synthesis

What is the polymer of monosaccharides called?

polysaccharides

What are the two types of polysaccharides?

storage and structural

What is the purpose of a structural polysaccharide?

Organisms build strong materials from __________ polysaccharides.

Ex. chitin and cellulose

What is the purpose of a storage polysaccharide?

Plants use this polysaccharide to store sugar in the form of starch, and animals store sugar in the form of glycogen

What is the carbohydrate’s main functions?

short term energy storage and providing building material to cells and organisms

Where do animals store glycogen?

in muscle tissue and liver

What do amino acids form when bonded, and what are those bonds called? (2 answers)

Protein (also called polypeptides), peptides

What do proteins do/what are their functions?

defense, transport, cellular communication, movement, structural support (etc.)

How many different types of amino acids are there?

20

Why do amino acids differ in properties?

contains different side chains called R groups

What are the 3 different categories of R groups and why are they distinct?

1. Nonpolar and hydrophobic

2. Polar and hydrophilic

3. Ionic and hydrophilic

What is the primary level of proteins?

a linear sequence of amino acids

What is the secondary level of proteins?

hydrogen bonding between amino acids causes the formation of alpha helices (coils) and beta pleated sheets (folds)

What is the tertiary level of proteins?

has a 3 dimensional (globular shape), determined by interactions between side chains such as:

• hydrophobic interactions

• Hydrogen bonding

• Ionic and covalent bonding

What is the quaternary level of proteins?

multiple polypeptides, only found in some proteins

What is the protein that transports oxygen in blood?

hemoglobin

Which element is important in folding proteins?

sulfur

Carbohydrates have ___ calories per gram

4 calories per gram

Protein has ___ calories per gram

four calories per gram

Fats have ___ calories per gram

9 calories per gram

What 3 elements are the monomers of carbohydrates made with? What is the ratio/empirical formula?

carbon, hydrogen, and oxygen in a 1:2:1 ratio

How many amino acids does hemoglobin contain?

146

How many amino acids need to change in hemoglobin for the condition sickle-cell anemia?

1

What is the loss of a protein’s functional structure due to environmental conditions called?

denaturation

What is the function of a enzymatic protein?

proteins that act as catalysts to accelerate chemical reactions within cells

What is the function of a transport protein?

proteins embedded in the cell membrane that control the movement of substances in and out of the cell

What is the function of a contractile and motor protein?

proteins that help cells move and help move material inside cells & proteins that are found in muscles and are responsible for muscle contraction

What is the function of a receptor protein?

proteins that bind to chemical signals and initiate a cell response

What is the function of a hormonal/signaling protein?

proteins that are released into the blood and bind to receptors on cells throughout the body to regulate the activity of an organism

What is the function of a defense protein?

proteins, such as antibodies, assist the immune system in destroying viruses and bacteria and protecting organisms from infection

What is the function of a structural protein?

proteins that are long and fibrous which play structural roles in organisms

• ex. keratin, collagen, cytoskeleton proteins

What is DNA and what does it stand for?

deoxyribonucleic acid; genetic material that stores information for its own replication and for the sequence of amino acids in proteins

What is RNA and what does it stand for?

ribonucleic acid; performs a wide range of functions within cells which include protein synthesis and regulation of gene expression

What 3 parts make up a nucleotide?

phosphate group, a pentose (5-carbon) sugar, and a nitrogen-containing (nitrogenous) base

What are the two families of nitrogenous bases?

pyrimidines and purines

What are pyrimidines (a type/family of nitrogenous base)?

bases with one ring and include cytosine (C), thymine (T), and uracil (U)

What are purines (a type/family of nitrogenous base)?

bases with two rings and include adenine (A) and guanine (G)

Which nucleic acid is Thymine only found in? (DNA/RNA)

DNA

Which nucleic acid is Uracil only found in? (DNA/RNA)

RNA

Is DNA parallel or antiparallel?

antiparallel

Why is ATP (adenosine triphosphate) considered a high-energy molecule?

it has additional unstable phosphate bonds which are easily broken through hydrolysis to generate energy from the reaction

What 4 elements are found in lipids?

carbon, hydrogen, oxygen, phosphorus

Can lipids form polymers?

no, because the monomers cannot repeatedly bind to one another to form chains

What are the most biologically important lipids?

fats, phospholipids, and steroids

What are fats made of?

triglycerides (large nonpolar molecules)