biology unit 2: biological molecules

lipids

- also known as fats, come in different forms in your body and contain the most energy of all the organic compounds. when lipids are burned for fuel, you get more energy than if you burned the other organic molecules. - fats take the form of phospholipids and cholesterol, both important parts of cell membranes; waxes that provide plants and animals with a protective layer; hormones that signal different functions in your body; vitamins that aid in different cell functions; and steroids, which are important in a number of physiological processes

carbohydrates

- comprise the largest number of organic molecules in organisms. basically sugars - simplest sugar is glucose, used to provide fuel for many types of organisms - fructose in fruits, galactose in milk, maltose in vegetables, sucrose in table sugar - your body contains an enzyme called amylase, which breaks down carbohydrates in the food you eat into glucose, which your cells can use as energy

proteins

- most versatile of all the organic molecules, making up many structures and executing various functions in organisms. - made up of building blocks called amino acids. about 20 different amino acids combine to form all the various types of proteins. they all have almost the same composition except in the R group. - when a protein is made, the protein comes together one amino acid at a time within the ribosome. - four levels of structure: bonding amino acids to one another, folds in certain areas in the protein, the 3D look of the protein, and a structure consisting of smaller protein subunits chemically bonded together to form a larger protein

What can cause proteins to denature (lose their shape)? Select all that apply.

1. Severe change in temperature (too hot or too cold) 2. Exposing them to hazardous chemicals

Which of the following describes the 3rd level and 4th level shapes of a protein? Select two.

1. Twists and folding of the secondary shape 2. clusters that are linked together to form a giant molecule

true about carbohydrates

1. starches and sugars are examples of carbohydrates 2. living things use them as their main source of energy 3. plants and some animals use them for strength and rigidity.

the usual ratio for a carbohydrate is

1:2:1

A phospholipid has how many fatty acid chains

2

How is a phospholipid formed?

2 fatty acids + Glycerol + phosphate group

How many total amino acids exist?

20

How many fatty acids are found in one triglyceride.

3

How is a triglyceride formed?

3 fatty acids + Glycerol through Dehydration synthesis

the glucose molecule has

6 Carbon atoms 12 Hydrogen atoms 6 Oxygen atoms

What is the difference between a polypeptide and a protein?

A polypeptide is a sequence of amino acids but a protein is when a polypeptide is folded into its shape.

Define denaturation. What effect does this have on a protein?

A process in which a protein unravels and loses its specific individual shape, thus losing its function. Excessive heat can denature many proteins.

How is a steroid structurally different from a fat? Why are they both lipids?

A steroid has a fused ring structure and is a lipid because it is also hydrophobic.

What is dextrose?

An aqueous solution of glucose. Monosaccharides, especially glucose, are the main fuel molecules for cellular work. Because cells release energy from glucose when they break it down, dextrose may be injected into the bloodstream of sick or injured patients. The glucose provides an immediate energy source to tissues in need of repair.

What is the difference between a saturated fatty acid and an unsaturated fatty acid?

An unsaturated fatty acid has a hydrocarbon chain that contains one or more double bonds. A fatty acid that has no double bonds in its hydrocarbon chain is called a saturated fatty acid.

Why can't humans digest cellulose?

Animals do not have enzymes that can hydrolyze the glucose linkages in cellulose, so it is not a nutrient for humans, though it does contribute to digestive health.

Make connections: Carbon forms the backbone of every major type of biological molecule,including carbohydrates, fats, proteins, and nucleic acids. How does carbon's high valence relate to its ability to form these large and complex biomolecules?

Carbon has four electrons in its outermost shell, with these it forms covalent bond with other elements by sharing electrons with them.The elements that made up the biological molecules react easily with carbon, giving rise to different types of macromolecules. Besides this, carbon is flexible and can conform to any shape whether linear, coiled, ring or ball form.

all Carbohydrates contain

Carbon, Hydrogen and Oxygen

What is the function of cholesterol?

Cholesterol is a common component in animal cell membranes and is the precursor for making other steroids.

What is high fructose corn syrup and how do we make it?

Corn starch is hydrolyzed to glucose, then enzymes convert glucose to fructose. This fructose is combined with corny syrup to produce high-fructose corn syrup.

a shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture _____.

DNA

What are the two types of Nucleic Acids

DNA and RNA

nucleic acids

DNA and RNA. make proteins that are present in most structures and perform almost every function in your body

hereditary (nucleic acids)

DNA is for prokaryotes and eukaryotes RNA is for viruses

What is the polymer of a Nucleotide?

DNA or RNA

How can you build a disaccharide? What process is used?

Disaccharide is built from two monosaccharide monomers through a dehydration reaction.

List three lipids.

Fats, phospholipids, and steroids.

the two other important monosaccharides are

Fructose and Galactose

C pairs with

G

When you look at fructose and glucose, they have the same chemical formula. What makes them different if they have the same formula? What do we call these?

Glucose and fructose are isomers, meaning they only differ in the arrangement of their atoms. In this case, the positions of the carbonyl groups are different. The shape of molecules is very important, so minor differences like these give isomers different properties, such as how they react with other molecules.

What smaller molecules make up a fat?

Glycerol and fatty acids.

What does it mean when you see "hydrogenated vegetable oils" on a label? What did they do to your food?

It means the unsaturated fats in the vegetable oil have been converted to saturated fats by adding hydrogen. This creates trans fats, which is associated with health risks.

What are three functions of fats?

Long term energy storage, insulation, and protection of vital organs.

For a protein to achieve its globular shape it must fold properly. What could happen if a protein misfolds into a different shape?

Many diseases like Alzheimer's and Parkinson's involve many folded proteins.

What does a fatty acid contain?

Methyl group hydrocarbon chain Acid group

Explain why a phospholipid is not considered entirely polar or entirely nonpolar as a molecule?

One end is hydrophilic and the other end is hydrophobic.

channels

Passive: Aquaporins, gated channels, glucose channels Active: K+/Na- ATPase pumps - in cell membranes

What is the function of polysaccharides?

Polysaccharides are macromolecules, polymers of hundreds to thousands monosaccharides linked together by dehydration reactions. They may function as storage molecules or as structural compounds.

What is different in every amino acid?

R group

energy molecules (energy currency) (nucleic acids)

RNA nucleotides (ATP)

Explain why unsaturated fats are liquid at room temperature while saturated fats are solid?

Saturated fats lack double bonds, so they are packed closely together, making them solid at room temperature. The kinks in unsaturated fatty acids tails prevent them from packing close together, so they are liquid at room temperature.

Name 4 polysaccharides and their functions?

Starch is a storage polysaccharide in plants consisting of long chains of glucose monomers. Glycogen is stored in animals and is stored as granules in your liver and muscle cells, which hydrolyze the glycogen to release glucose when it is needed. Cellulose, the most abundant organic compound on Earth, is a major component of the walls that enclose plant cells. Chitin is a structural polysaccharide used by insects and crustaceans to build their exoskeleton. It is also found in the cell walls of fungi.

A pairs with

T

What about fats makes them hydrophobic?

The non-polar C-H bonds in the hydrocarbon chains are the reason fats are hydrophobic.

Describe the structure of a phospholipid.

The two ends of a phospholipid have different relationships with water, causing the aggregation of several phospholipid molecules into a membrane.

What is the function of phospholipids?

They are a major component of cell membranes.

Describe 7 functions of proteins. Try to give an example of each and describe the function.

They are enzymes, like lactose, which regulate almost all chemical reactions in your cells. There are also transport proteins that move sugar molecules and other nutrients into your cells. Defensive proteins move through your bloodstream, for example the antibodies of the immune system. Signal proteins help coordinate your body's activities, like hormones and other chemical messengers. Receptor proteins, like growth hormones, are built into cell membranes and they receive and transmit signals into your cells. Structural protein collagen forms the long, strong fibers of connective tissues and are found in hair, tendons, and ligaments. Storage proteins supply amino acids to developing embryos, the protein found in eggs and seeds are examples.

What does it mean when they say most carbohydrates are hydrophilic? What gives them this hydrophilic property?

They are hydrophilic because of the many hydroxyl groups attached to their sugar monomers.

Why would anyone want to hydrogenate an unsaturated fat?

To make the oil solid and turn it into margarine.

Why is there a ban on trans fats?

Trans fats presented greater health risks than saturated fats and it was required to list trans fats on food labels, but food sold in restaurants and schools does not come with labels, so trans fats were banned.

What makes up the quaternary structure of a protein?

Two polypeptides or proteins bonded together.

dehydration reaction

a chemical reaction in which molecules combine by removing water

gene

a discrete unit of vast inheritance that programs the amino acid sequence of a polypeptide.

polymers

a molecule composed of linked monomers

polynucleotide

a nucleic acid polymer. built from its monomers by dehydration reactions

a glucose molecule is to starch as

a nucleotide is to a nucleic acid. nucleotides are monomers of nucleic acids, just as glucose is the monosaccharide of starch.

contractile

actin; myosin - moving muscles

signaling molecules

adenylate cyclase - can signal within cells or between cells.

Osmoregulators (Fluid Balance)

albumin - Liver-detoxifies poisons, does some other stuff. - Helps reabsorb fluids that left the blood vessels.

glycogen

also known as animal starch, this molecule is stored in your muscles and supplies the energy for muscle contraction, and thus, movement.

both DNA and RNA consist of

alternating molecules of phosphate and sugar

Proteins are made out of ________

amino acids

What are the building blocks of proteins?

amino acids

protein monomers

amino acids

most proteins are soluble in the aqueous environment of a cell. knowing that, where in the overall three-dimensional shape of a protein would you expect to find amino acids with hydrophobic R groups?

amino acids with hydrophobic R groups are most likely to be found clustered together in the interior of a protein, sheltered from the surrounding water.

_______ help fight disease

antibodies

immune response

antibodies - Create antibodies that will stop bacteria in its tracks.

biomolecules

are building components of life

hydrolysis

breaking down complex molecules by the chemical addition of water. digestion process. reverse dehydration reaction

monomers

building blocks of polymers

organic molecules contain

carbon and hydrogen chemically linked to one another in long chains. these atoms ability to attach to one another allows for the creation of innumerable compounds conductive to life.

carbonyl group

carbon atom linked by a double bond to an oxygen atom. if this group is at the end of a carbon skeleton, the compound is called an aldehyde; if it is within the chain, the compound is called a ketone.

What atoms make up carbohydrates?

carbon, hydrogen, oxygen

What three elements make up lipids?

carbon, hydrogen, oxygen

of the following functional groups, which are polar, tending to make organic compounds hydrophilic?

carbonyl, amino, and hydroxyl groups

which two groups of amino acid participates in forming a bond with another amino acid?

carboxyl group and amino group

healing

clotting factors - 9 clotting factors and each one catalyzes the next one to be active. - Form a patchwork of fibers.

structural

collagen; ligaments - collagen very strong - ligaments hold bones together, does not stretch easily

a polysaccharide is also known as a _______________ sugar.

complex sugar

organic compounds

compounds containing carbon. ex. DNA, methane, ethanol, sucrose

inorganic compounds

compounds that do not contain carbon. some exception. ex. table salt, diamond, silver, sulfur

methyl group

consists of a carbon bonded to three hydrogen atoms.

carboxyl group

consists of a carbon double bonded to an oxygen atom and bonded to a hydroxyl group. the carboxyl group acts like an acid by contributing H^+ to a solution, becoming ionized. compounds that contain this group are called carboxylic acids.

hydroxyl group

consists of a hydrogen atom bonded to an oxygen atom, which is bonded to the carbon skeleton. ethanol is an organic compound containing hydroxyl groups. compounds that contain this group are called alcohols.

phosphate group

consists of a phosphorus atom bonded to four oxygen atoms. usually ionized and attached to the carbon skeleton by one of its oxygen atoms. compounds with this group are called organic phosphates. they are often involved in energy transfers

what is the name of the reaction which bonds 2 monosaccharides together?

dehydration synthesis

what is the process by which macromolecules are formed?

dehydration synthesis/polymerization

cellulose is not

digestible

healthy sources of lipids

eggs, avocados, fish, nuts, olive oil

_______ control the rate of reactions and regulate cell processes

enzymes

organic catalysts

enzymes - Can only speed up a reaction that can occur, not enter the reaction. - ex. manganese dioxide added to hydrogen peroxide will break it down immediately into water and oxygen. manganese dioxide is a catalyst.

True or False: A hydrophobic substance is attracted to water.

false

True or False: All fats are bad for you and you should never eat anything with fat in it.

false

the hydrophobic portion of the cell membrane is

fatty acid tail

unhealthy sources of lipids

fatty cuts of meat and poultry, dairy

another name for cellulose is

fiber

How many levels of protein shape are there?

four levels

monosaccharide ex.

galactose, glucose, fructose

glycogen is a stored form of____________.

glucose

what substance is the repeating unit that makes up starch, cellulose and glycogen?

glucose

which monosaccharide is the most important carbohydrate?

glucose

lipids monomers

glycerol and fatty acids

lipids are composed of 1 molecule of _________ and 3 molecules of ________

glycerol, fatty acids

amino group

has a nitrogen bonded to two hydrogens and the carbon skeleton. it picks up an H^+ from a solution, acting as a base. organic compounds with this group are called aminos

unsaturated fats

have double bonds in their fatty acid chains

transport function

hemoglobin; transferrin - hemoglobin transports oxygen and is a quaternary structure. - transferrin transports iron. - made by the liver - transports to storage.

functions of nucleic acids

hereditary, catalytic, protein synthesis, energy molecules

organize DNA

histones

chemical messengers

hormones - Lipid hormones are much more potent than protein hormones.

lipids are made mostly from carbon and ______

hydrogen

what are the two DNA chains held together by?

hydrogen bonds between their paired bases. individually, they are weak, but together they zip the strands together into a very stable double helix.

nitrogenous bases form

hydrogen bonds in DNA

what other elements are usually found with carbon in organic compounds?

hydrogen, oxygen, nitrogen

molecules not associated with living things are:

inorganic compounds. include salts, metals, substances made from single elements and any other compounds that don't contain carbon bonded to hydrogen.

what makes a fatty acid an acid?

it has a carboxyl group that can donate an H+ to a solution

the structure of DNA accounts for what?

its function of transmitting genetic information whenever a cell reproduces.

the disaccharide mainly found in milk is

lactose

secondary protein structure

local folding of the polypeptide chain into helices or sheets. usually 2-dimensional.

protein synthesis (nucleic acids)

mRNA; rRNA; tRNA

Many of the molecules in living cells are so large that they are known as

macromolecules

DNA (deoxyribonucleic acid)

makes up genes and is one of the two types of polymers called nucleic acids. - provides directions for its own replication so as a cell divides, its genetic instruction is passed to the daughter cells. - a double helix in which 2 polynucleotides wrap around eachother

What is a polypeptide?

many amino acids bonded together

RNA

many different shapes depending on its function. it can travel throughout cell to where it is needed. helps DNA make proteins

good sources of protein

meats, eggs, dairy products, legumes, nuts, quorn, and certain "ancient grains."

nucleotides

monomers of nucleic acids -contains 5-carbon sugar, a negatively charged phosphate group, and a nitrogenous base. - each DNA nucleotide has one of four different nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G). - RNA nucleotides contain the bases: A, C, and G but uracil (U) replaces T

carbohydrate monomer

monosaccharide

a disaccharide is produced when two _____________ are bonded together.

monosaccharides

single sugar molecules are also called

monosaccharides

storage

myoglobin; ferritin - myoglobin stores oxygen - ferritin stores iron

proteins are macromolecules that contain ______ as well as carbon, hydrogen, and oxygen

nitrogen

Lipids are

nonpolar molecules

life cannot exist without:

nucleic acids, proteins, carbohydrates, lipids

nucleic acids monomer

nucleotides

nucleic acids monomers

nucleotides

Which is an example of an unsaturated fatty acid

olive oil

catalytic (nucleic acids)

only RNA acts a catalyst called ribozymes

molecules associated with living things are:

organic compounds. these include nucleic acids, fats, sugars, proteins, enzymes, and hydrocarbon fuels

Hydrophilic R groups will fold to the ________.

outside

what is the name of the bond formed between 2 amino acids called?

peptide bond

The hydrophilic portion of the cell membrane is the

phosphate head

Which type of lipid is one of the main structural components of all cell membranes?

phospholipids

which of the following substances is a major component of the cell membrane of a fungus?

phospholipids

How do plants and animals store excess sugar?

plants store them as starch, animals store them as glycogen

buffers (acid - base balance) in the plasma

plasma proteins - resists a pH change

What are polysaccharides?

polymers of many monosaccharides linked by dehydration reactions

phosphates bond to form

polynucleotide chains

more than one double bond between carbon atoms

polyunsaturated fatty acids

which structural level of protein would be least affected by a disruption in hydrogen bonding?

primary structure

quarternary protein structure

protein consisting of more than one amino acid chain

The tertiary structure is formed by the interactions of the different ______.

r groups

Which type of lipid is solid at room temperature and is found in foods like cheese and red meat?

saturated fatty acids

single bonds between carbons

saturated fatty acids

primary protein structure

sequence of a chain of amino acids. Ppoteins are made on ribosomes. Primary structures are just what comes off a ribosome. Not functional because a protein that can function has to form shapes and fold and bend, creating bonds.

DNA

shaped like a twisted ladder. typically remains in nucleus of cell. more stable than RNA. your genes are made up of this, each gene provides codes for making a specific protein

monosaccharides are also called

simple sugars

Are all steroids bad for you?

some are bad, some good

three important polysaccharides are

starch, glycogen and cellulose

Which type of lipid includes hormones, cholesterol, and chlorophyll?

steroids

although each of the monosaccharides discussed have the same number of Carbon atoms (6), Hydrogen atoms (12) and Oxygen atoms (6) their _________________ are slightly different.

structures

the three important disaccharides are

sucrose, lactose and maltose

what are nucleotides made of?

sugar, phosphate group, nitrogen base

starch, cellulose and glycogen are all made up of the same repeating unit. in what way do these three substances differ from one another?

the bonds between the glucose

functional groups

the first five of six important chemical groups. they affect a molecules function by participating in chemical reactions. they are polar, causing the compounds that have them hydrophilic and soluble in water. the sixth group is nonpolar and not reactive but affects molecular shape and function

What determines the function of each protein?

the function is determined on their individual shapes.

RNA (ribonucleic acid)

the second type of nucleic acid, an intermediary that DNA works through to build proteins. - interacts with protein-building machinery and translates the gene's instructions into the amino sequence of a polypeptide - usually consists of a single polynucleotide strand

properties of an organic compound depend on

the size and shape of its carbon skeleton and the groups of atoms that are attached to that skeleton

cows can derive nutrients from cellulose because

their digestive tract contains prokaryotes that can hydrolyze the bonds of cellulose

Why aren't lipids true polymers?

there are no monomers that repeat themselves in lipids

Which of the following is true about lipids?

they do not dissolve in water

sucrose is broken down in your intestine to the monosaccharides glucose and fructose, which are then absorbed into your blood. what is the name of this type of reaction?

this is a hydrolysis reaction, which consumes water.

tertiary protein structure

three-dimensional folding pattern of a protein due to side chain interactions

What nitrogenous base is RNA missing?

thymine

What is another name for a fat?

triglyceride

True or False: When a protein loses its shape it becomes denatured.

true

cholesterol is a steroid

true

at least one double bond between carbon atoms

unsaturated fatty acid

Which type of lipid is a liquid at room temperature and comes from foods like nuts and fish?

unsaturated fatty acids

general structure of an amino acid

very nice

which molecule is lost when two monosaccharides are bonded together?

water

Which type of lipid is found in human ears to help protect our eardrums?

waxes