Biology unit 1.1.3: Chemical structure of carbohydrates, lipids, proteins, nucleic acids

Any molecule containing __ is called “organic”

carbon

made of building blocks called monomers

organic molecules

monomer

one molecule

polymer

many molecules linked together

many monomers link together to form ____

polymer (whole molecule)

How many classes of organic molecules?

4 classes

what are carbohydrates made of?

made only of carbon, oxygen, & hydrogen; simple but can form lots of complex things

What are carbohydrates monomer name?

monosaccharide

Example of a monosaccharide

glucose

what are carbohydrates polymer name?

polysaccharide

example of a polysaccharide

starch

Common lipids

waxes (water barrier), fats (energy storage), phospholipids (cell membranes), steroids (hormones)

What are proteins monomer name?

amino acids

what are proteins polymer name?

Polypeptide

peptide bond

holds amino acids together

monomer name of nucleic acids

nucleotide

How many types of nucleic acids?

two types (DNA & RNA)

DNA

Deoxyribonucleic acid; genetic material found in all living organisms

RNA

ribonucleic acid; mostly involved in protein synthesis

What is the primary function of nucleic acids?

information storage

What are nucleotides made of?

1 nitrogen base, 1 sugar (deoxyribose or ribose), & 1 phosphate group

What are the 5 types of nitrogen bases?

Adenine (A), Thymine (T, only in DNA), Uracil (U, only in RNA), Cytosine (C), Guanine (G)

Nucleotide pairs: A - _

A-T or A-U

Nucleotide pairs: C->_

C-G

What is another name for nucleotide pairs?

base pairs

Base pairs joined in center by __

Hydrogen bonds

What are galactose and fructose examples of?

Examples of monosaccharides

Monosaccharides can exist as a linear chain or as ring shaped molecules; in aqueous solutions they are found in what form?

ring forms

disaccharides

when 2 monosaccharides undergo a dehydration reaction (also known as a condensation reaction or dehydration synthesis)

What happens when 2 monosaccharides undergo a dehydration reaction?

During this process, the hydroxyl group of one monosaccharide combines with the hydrogen of another monosaccharide, releasing a molecule of water and forming a covalent bond

Glycosidic bond

covalent bond formed between a carybohydrate molecule and another molecule (cann be of the alpha or the beta type)

What are some examples of common disaccharides?

lactose, maltose, sucrose

Lactose

disaccharide consisting of the monomers glucose and galactose

Maltose / malt sugar

disaccharide formed by a dehydration reaction between 2 glucose molecules

Sucrose (table sugar)

disaccharide composed of the monomers glucose and fructose (most common disaccharide)

polysaccharides

long chain of monosaccharides linked by glycosidic bonds

What are some examples of polysaccharides?

Starch, glycogen, cellulose, chitin

Starch

stored form of sugars in plants; made up of a mixture of amylose and amylopectin (both polymers of glucose)

Where do plants store their excess glucose?

 Plants are able to synthesize glucose, and the excess glucose, beyond the plant’s immediate energy needs, is stored as starch in different plant parts, including roots and seeds

What is starch broken down into when consumed by humans?

When starch is consumed by humans it is broken down by enzymes, such as salivary amylases into smaller molecules such as maltose and glucose. the cells can then absorb the glucose

What is starch made up of?

Glucose monomers that are joined by α 1-4 or α 1-6 glycosidic bonds (The numbers 1-4 and 1-6 refer to the carbon number of the two residues that have joined to form the bond)

Amylose

 starch formed by unbranched chains of glucose monomers (only α 1-4 linkages)

Amylopectin

branched polysaccharide (α 1-6 linkages at the branch points)

Glycogen

the storage form of glucose in humans and other vertebrates

What is glycogen made up of?

made up of monomers of glucose

glycogen is the animal equivalent of ____

starch

What happens to glycogen when blood glucose levels decrease?

glycogen is broken down to release glucose in a process known as glycogenolysis

Cellulose

The most abundant natural biopolymer; made up of glucose monomers that are linked together by  β 1-4 glycosidic bonds

Cell wall of plants is mostly made of ___

cellulose (provides structural support to the cell)

Wood and paper are mostly ___ in nature

cellulosic

What gives cellulose its rigidity and high tensile strength?

every other glucose monomer in cellulose is flipped over, and the monomers are packed tightly as extended long chains.

What is chitin?

a type of polysaccharide found in bug exoskeletons & fungal cell walls

Lipids

diverse group of compounds that are largely nonpolar in nature; the building blocks of many hormones and are an important constituent of all cellular membranes

Are non-polar molecules hydrophobic or hydrophillic?

hydrophobic/insoluble in water

How do cells store energy?

Cells store energy for long term use in the form of fats

__ Provide insulation from the environment for plants and animals

lipids (keep aquatic birds and mammals dry when forming a protective layer over fur or feathers because of their hydrophobic nature)

what are some examples of lipids?

fats, oils, waxes, phospholipids, & steroids

What are the 2 main components of fat molecules?

glycerol & fatty acids

What is glycerol?

organic compound (alcohol) with 3 carbons, 5 hydrogens, & 3 hydroxyl (OH) groups

Fatty acids

long chain of hydrocarbons to which a carboxyl group is attached

What is the number of carbons in the fatty acid?

ranges from 4-36 (most commonly containing 12-18)

How are fatty acids attached to each of the 3 carbons of the glycerol molecule in a fat molecule?

with an ester bond through an oxygen atom; During this ester bond formation, three water molecules are released

What are triacylglycerols or triglycerides another name for

Another name for fats

In a fatty acid chain, if there are only single bonds between neighboring carbons in the hydrocarbon chain, the fatty acid is said to be ___

saturated

saturated fatty acid

saturated fatty acids are saturated with hydrogen; in other words, the number of hydrogen atoms attached to the carbon skeleton is maximized; ex: stearic acid

Most unsaturated fats are liquid at room temperature & are called ___

oils

monosaturated fat

An unsaturated fat that has a double bond in the molecule; ex: olive oil

polyunsaturated fat

an unsaturated fat with more than one double bond; ex: canola oil

When a fatty acid has no double bonds why is it known as a saturated fatty acid?

because no more hydrogen may be added to the carbon atoms of the chain

long straight fatty acids with single bonds tend to be solid or liquid at room termperature?

tend to get packed tightly and are solid at room temperature

What type of cells do mammals store fat in?

specialized cells called adipocytes;  where globules of fat occupy most of the cell’s volume

Where do plants store fat or oil?

stored in many seeds and used a source of energy during seedling development

cis fat

If hydrogens are present in the same plane

trans fat

if the hydrogen atoms are on two different planes

The __double bond causes a bend or a “kink” that prevents the fatty acids from packing tightly, keeping them liquid at room temperature

cis

What are waxes made up of?

long fatty acid chains esterified to long-chain alcohols

Phospholipids

Major parts of the plasma membrane (outermost layer of animal cells);  molecule with two fatty acids and a modified phosphate group attached to a glycerol backbone

What is the phospholipid head?

hydrophilic phosphate containing group

What are the phospholipid tails?

hydrophobic fatty acid chains

____ are responsible for the dynamic nature of the plasma membrane

phospholipids

steroids

hydrophobic and insoluble in water

What is the most common steroid?

cholesterol

proteins

Proteins may be structural, regulatory, contractile, or protective; they may serve in transport, storage, or membranes and they may be toxins or enzymes.

All proteins are polymers of ___

amino acids, arranged in a linear sequence

Enzymes

type of protein that works as catalysts in biochemical reactions (like digestion)

catabolic enzymes

enzymes that break down their subtrates

anabolic enzymes

enzymes that affect the rate of reaction

all enzymes __ the rate of reaction and, therefore, are considered to be organic catalysits

increase

Salivary amylase is an example of what?

An enzyme

Hormones

chemical signaling molecules, usually small proteins or steroids, secreted by endocrine cells that act to control or regulate specific physiological processes, including growth, development, metabolism, and reproduction; For example, insulin is a protein hormone that helps to regulate the blood glucose level

Proteins __ are critical to the proteins function

shapes

How is protein’s shape maintained?

protein shape is maintained by many different types of chemical bonds; Changes in temperature, pH, and exposure to chemicals may lead to permanent changes in the shape of the protein, leading to loss of function, known as denaturation

All proteins are made up of different arrangements of __

the same 20 types of amino acids

amino acids

monomers that make up proteins

How many amino acids are present in proteins?

20 amino acids

What is the structure of amino acids?

Each amino acid has the same fundamental structure, which consists of a central carbon atom, also known as the alpha (α) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom; Every amino acid also has another atom or group of atoms bonded to the central atom known as the R group

Where does the name “amino-acid” come from?

derived from the fact that they contain both amino group and carboxyl-acid group in their basic structure

How many amino acids are considered essential to humans?

10; considered essential amino acids in humans because the human body cannot produce them and they are obtained from the diet.

For each amino acid the __ is different

R group (or side chain)

What does the chemical nature of the side chain of an amino acid determine?

the nature of the amino acid (whether it is acidic, basic, polar, or nonpolar)