Chapter 2: Chemical Components of Cells

What does an atom consist of?

A nucleus thats surrounded by an electron cloud

Why is carbon important?

it is important in helping distinguish whether something is organic or inorganic

what are the 4 most relative abundant element present in the human body?

H, C, O, and N. With more than 60% of H atoms being present

What do organisms expend energy for?

In order to concentrate elements found in relatively low amounts in the earths crust to use them

What do each electron shell have?

A defined saturation point, which is the max # of electrons that can be held

How many electrons can the first, second, and third shell hold?

2, 8 ,18

How is a covalent bond formed?

When 2 atoms come together and share one or more of their out-shell electrons

How are ionic bonds formed?

When an atom gives their electron to another, resulting in 2 ions with charges and are held together by electrostatic attraction

how does electrostatic attractions occur?

Both between fully charged groups (ionic bond) and between partially charged groups on polar molecules

How are hydrogen molecules formed?

Two hydrogen atoms share electrons at a defined length and form a covalent bond

What if there is a single covalent bond between 2 atoms?

the molecule can freely rotate

What if there is a double covalent bond between 2 atoms?

the molecules cannot freely rotate

What molecules do noncovalent hydrogen bonds form between?

Between water molecules and other polar molecules

What molecules do hydrogen bonds form between in cells?

Between molecules that contain an oxygen or nitrogen atom

How are large molecules able to bind with one another? (Such as a protein with another protein)

Through noncovalent bonds when both molecules surfaces match well with one another, allowing them to withstand thermal motion and prevent separation

Which kind of bond has the shortest bond length? what abt the longest??

Covalent bonds; van der waals attractions

What kind of ability do some polar molecules have?

The ability to form acids and bases in water due to protons being able to move from one molecule to another within an aqueous solution

Example of a polar molecule forming acids and bases?

Acetic acid in water becoming acetate and water becoming hydronium due to a proton going to water

What is a carbon skeleton|?

A series of carbon atoms bonded together in a chain to form various structures

• Such as": chains, branched trees, or rings

What are hydrocarbons?

a nonpolar stable compound made of carbon and hydrogen

What is the acidity of a solution defined by?

By the concentration of H3O it possess

What occurs as H3Os concentration increases?

OH- concentration decreases

What are the 4 major building blocks of small organic cells?

• Sugars

• fatty acids

• amino acids

• nucleotides

Why sugar important?

provides energy and are structural molecules

why are fatty acids important?

acts as an energy source

why are amino acids important?

Help build proteins and carry out 90% of the creation of proteins

Why are nucleotides important?

Essential building blocks for DNA/RNA

What do the 4 major building blocks of small organic cells act as?

As the subunits for larger organic molecules, which includes macromolecules and other molecular assemblies of the cell

What are sugar subunits for?

For polysaccharides and oligosaccharides

• Polysaccharides being long chains of repeating sugar subunits

• Oligosaccharides being short chains of repeating sugar sub units

what are fatty acids subunits for?

For fats and membrane lipids

What are amino acids subunits for?

For proteins

What are nucleotides subunits for?

For nucleic acids

What is the structure of glucose made of?

Of hydrogen, oxygen, and carbon

What is a condensation reaction?

A reaction where water is lost, allowing for 2 molecules to join together as a larger molecule and generating ATP

What is a hydrolysis reaction?

A reaction where water is introduced, breaking bonds of larger molecules and releasing ATP, resulting in 2 separate molecules

What does the structure of fatty acids contain?

They contain a hydrophilic carboxylic acid head and a hydrophobic hydrocarbon tail

What are fatty acids a major component for?

Major component for lipids

What are the 2 kinds of fatty acid tails?

Saturated and unsaturated?

What is a triacylglycerol molecule?

A molecule that is stores 3 fatty acid chains, that are either saturated or unsaturated, to a glycerol molecule

• and is able to store energy

What occurs if too much fat is taken into the body?

Cholesterol in the blood rises and causes clogging in the arteries, increasing the risk of heart attacks/strokes

What is the most abundant lipid called?

The phospholipid

What does the structure of a phospholipid contain?

A hydrophilic head and 2 hydrophobic fatty acid tails that are either saturated or unsaturated

What does the hydrophilic head of a phospholipid consist of?

It consists of a polar group, phosphate group, and a glycerol group

What are phospholipids responsible for?

For the formation of cell membranes, with Phosphatidylcholine being the most common phospholipid in the membrane

What do the levels of saturation of the phospholipid tails determine?

They determine the fluidity of the membrane

How many amino acids do proteins contain?

They contain 20 different kinds of amino acids

What does the structure of an amino acid consist of?

The structure consists of:

• An amino group

• A carboxyl group

• A side chain

• Alpha carbon atom

What is a side chain in an amino acid?

A group that can vary, from as simple as a single hydrogen to a methyl group

What are the 2 different forms of amino acids?

Nonionized amino acids and ionized amino acids

What are Nonionized amino acids?

Amino acids that has a side chain that cant gain or lose a proton

What are ionized amino acids?

Amino acids that has accepted/donated a proton, gaining a full charge that is either positive or negative

How are amino acids within proteins held together?

By covalent peptide bonds between a free carboxyl group of one amino acid and the amino group of another amino acid

What is ATP?

A crucial important energy carrier in the cell

What does the structure of ATP consist of?

It consists of:

• 3 phosphate groups

• Ribose sugar

• An adenine group

Where is most energy stored inside of cells?

Inside of ATP molecules

How is energy stored within a cell?

 ADP + Pi goes through condensation where a water molecule is lost and an input of energy helps reattach a phosphate group to back to the other two phosphate groups, resulting in ATP and energy stored inside it

How is energy released when a cell needs it?

ATP goes hydrolysis where a water molecule cleaves off the first phosphate group, causing stored energy to be released to the cell and breaking ATP down to ADP + Pi

How are nucleic acids formed from nucleotides?

Nucleotides form nucleic acids through condensation, allowing for the 5’ phosphate group of one nucleotide to join the 3’ hydroxyl group of another through phosphodiester bonding

What does the composition of a bacterial cell contain?

It contains 70% h2o and 30% chemicals

• the 15% of the chemicals being mainly proteins

What did chemists during early 20th century debate about regarding macromolecules and other large organic molecules?

Whether they were:

• Discrete particles made of an unusually large # of covalently linked atoms

• or a loose aggregation of heterogeneous small organic molecules held together by weak forces

How are marcomolecules studied?

Through the use of centrifugation

What is centrifugation?

A process where macromolecules are loaded into a tube and spined around using a metal rod at high speeds in a vacuum, generating forces exceeding 500k times and separating each one

How does the size of a molecule impact the centrifugation process?

Impacts centrifugal and the speed the molecules are moving at

What is boundary sedimentation?

A process where macromolecules settle to form a distinct boundary that are monitored to determine their size and shape

What is band sedimentation?

A process where macromolecules form a single sharp band that has a tight complex

What is the form of proteins that dont take on a rigid form?

Some proteins will be in a unfolded form and will fold once they find their proper partner that assists them to fold

What if the surfaces of macromolecules wanting to bind are a poor match?

Few covalent bonds will form and will eventually break apart due to thermal motion