bio exam 1 lectures 1-7

definition of life, basic chemistry of life, water, carbohhydrates, lipids and membranes, nucleic acids, central dogma and amino acids

what is biology

the study of living organisms and the processes that allow life to occur

why is life difficult to define

there are many properties that define life within each of those properties are subproperties

characteristics of living organisms

maintain homestatis

made up of cells

metabolism

exist in populations that evolve over time

stores information that enables them to develop and maintain themselves function and reproduce

the four unifying principles of biology

cell theory- all living things are made up of cells, cells are the basic unit of life, all cells come from other cells

homeostatis- maintenance of a city state by a physiological or behavioral feedback response. cells of a body internal environment that made up of extracellular fluid fluids. Cells, derived nutrients for extracellular fluid, and deposit waste into it. Serves needs of all cells and body.

Gene theory-treats and characteristics are passed from parents to offspring through discrete units, called genes, which are located on chromosomes and made of DNA

Evolution – processed by which the inherited traits of a population change over successive generations

basic chem terms

atomic number = number of protons

mass number = number of protons and neutrons

atomic weight = Number of protons electrons and neutrons

What are the four types of biomolecules found in all organisms

carbohydrates, lipids, proteins, and nucleic acids

All biomolecules are made up of what six elements? How many covalent bonds do they have?

carbon (C)-4

Hydrogen (H)-1

Nitrogen (N)-3

Oxygen (O)-2

Phosphorus (P)-5

Sulfur (S)-2

What is the difference between an atom that is reactive and one that is not reactive?

if an atom is not reactive then the valence shelf is full, so the atom is stable. If an atom is reactive, the valence shell is not filled and it's looking to bond.

What's the difference between an ionic bond and a covalent bond?

Ionic bond – attraction of opposite charges. They formed by electrical attraction, if one atom is a lot more electromagnetic than one of the other others a transfer of one or more electrons can take place.

Covalent bond – sharing of electron pairs. Forms in two atoms, attain stability by sharing electrons from valence shell. They are strong and there are 3-D geometry shape contributes to their biological function.

What's the difference between a polar and nonpolar covalent bond?

Polar covalent bond – occurs when the two atoms participating differ in electronegativity by 0.4. Unequal sharing of electrons

Non-polar covalent bond – two atoms are close to each other in electronegativity so they share electrons equally in the bond.

What is electronegativity? What two factors influence the electronegativity of an element.

the tendency of an atom to attract electrons when it occurs as part of a compound.

The electronegativity of an element is determined by how many positive charges an atom has because atoms with more protons are more attracted to electrons. The electronegativity is also determined by the distance between the nucleus and electrons in the valence shell because the closer the electrons, the greater the electronegative pull.

Describe the ways you can easily represent biomolecules

molecular formula – shows what elements are in a compound
Structural formula – shows how every element is connected in the compound

Line angle formula – omits, carbon and hydrogen from structure formula

What's a chemical reaction?

A+ B –> C + energy

A/B = reactants

–> = direction

C = products

First law thermodynamics

energy can't be created or destroyed, only transferred or transformed from one form to another

Potential energy

stored energy in an object because of its position, state or condition

Kinetic energy

energy and object has because of its motion when potential energy is released it turns into kinetic energy if an object is faster or heavier, it has more kinetic energy

Describe how cells store potential energy and how they transfer this energy into kinetic energy

store - molecular arrangements (chemical bonds) electrochemical gradients across membranes

Transfer – molecules rearrange or ions flow down the gradient to do cellular work

Bond energy

the amount of energy needed to separate two bonded or interacting atoms under physiological conditions

Bond energy and potential energy are inversely related

What kind of bonds contain the most bonded energy?

polar covalent

What kind of bonds contain the most potential energy?

ionic bonds

But if it's talking about covalent bonds, the nonpolar

What is the significance of carbon?

carbon is the most optimal basis for a biomolecular based on the following characteristics:

Carbon has four valence electrons

Carbon has an electronegativity of 2.55

Carbon has a moderate attraction for electrons

C – C bonds can be configured readily

Carbon can make many different molecules and is the backbone of biological molecules

What are two characteristics of water molecules that contribute to its unusual properties?

polar covalent bonds exist between oxygen and hydrogen, which allows water to form hydrogen bonds

Water molecules are been in a V shape because the oxygen pulls electrons from the hydrogen and possesses two non bonding orbitals

Are hydrogen bonds strong

individual hydrogen bonds are weak, they are so highly prolific and water that they're collective force is strong though. Thus they have an influential impact on biochemical behavior of biological molecules.

Waters density in a solid versus liquid state

ice is less dense than liquid water because hydrogen bonds forced water molecules to form an open shape that keeps them farther apart than when they're in a liquid stay. Water stays liquid beneath ice because of density which allows it to support life.

Waters high heat capacity

water needs a lot of energy to vaporize. It provides thermal stability for living organisms and ecosystems.

Cohesion and adhesion of water

cohesion – water pulls itself together because of hydrogen bonds. This allows for transpiration pool increase surface tension, which allows tiny organisms to walk and live on water surface.

adhesion –water can climb. This allows for capillary action, keeps tissues and fluids moisturized

Are covalent nonpolar bonds, covalent polar bonds, and ionic bonds, hydrophobic, or hydrophilic

covalent nonpolar – hydrophobic

Covalent polar -hydrophilic

Ionic bonds – hydrophilic

Are hydrogen bonds, hydrophobic interactions, Vanderwal interactions, polar or non-polar?

Hydrogen bonds – polar

Hydrophobic interaction – nonpolar

Vanderwall interaction – polar and nonpolar

Hydrophobic interactions occur when?

Nonpolar substances are excluded from water molecules in aqueous solutions

van der waals interactions

transit attractions between non-polar substances, driven by random fluctuations and electron distribution

Why are non-polar interactions important in biology

they helped to organize molecules and build self structures. They help molecules group together away from water, allowing them to make membranes shape proteins in organic cells.

Acids versus bases

acids – substances that release H + into a solution

Basis – substances that accept H + or release OH - ions

Strong acid/basis, ionize completely, weak acid/basis, only partially ionize so these reactions are easily reversible

pH

more H+ = descrease in pH = more acdic

less H+= increase in pH = more basic

pH= -log[H+]

Most biochemical reactions occur in solutions with a pH of seven

Describe the concept of homeostasis and how does this relate to pH in a living system?

homeostasis is the maintenance of internal consistency. If biological molecules lose or gain H + ions, it can upset homeostasis.

How do buffer systems help support homeostasis?

a buffer is a weak acid and it's corresponding base or weak base and it's corresponding acid. It minimize the effect that an added acid or base has on pH.

What would happen to the chemical system if there were a small increase in the concentration of H+, what effect would this happen on pH?

solution would become more pH would decrease

Biological molecules: macro molecules, monomer, and if the monomer are connected by covalent bonds

proteins – made up of amino acids and the monomer are connected by covalent bonds

Carbohydrates – linked together simple sugar monomer (monosaccharides). Made up of monosaccharides to form polysaccharides. The monomer are connected by covalent bonds.

Nucleic acids – four kinds of nucleotide monomer linked together in long chains. DNA/RNA. The monomers are connected by covalent bonds. Made up of nucleotides

Lipids – lipids make membranes. They form large structures from limited sets of smaller molecules. Built from glycerol and fatty acids. The monomers are not connected by covalent bonds because non-covalent forces, maintain the interactions between the lip and monomers that are held together by covalent bonds.

Compare condensation and hydrolysis reactions

condensation reactions – covalent bond between monomer is formed during condensation reactions, and water is produced. Energy is also required.

Hydrolysis reactions – covalent bond between monomer is broken during a hydrolysis reaction and water is consumed. Energy is also released.

What is a carbonyl

a functional group containing a carbon double bonded to oxygen

Keto and aldehyde are carbonyl functional groups

Why are carbonyls highly reactive?

C = O is strongly polar creating an electron for carbon that's easily attracted by electron seeking molecules

Monomers can vary from ___ to ___ carbons in size

3 to 7

The three most common functional groups found in monosaccharides are what? What is the influence of these functional groups only the behavior of a monosaccharide in water?

hydroxyl, aldehyde and keto

these functional groups cause a monosaccharide to dissolve easily and change its shape from a straight chain into a ring.

Monosaccharides can have the same chemical composition but different arrangements. What is this called?

structural isomers

What is the bond that joins two monosaccharides together?

Glycosidic bond

Provide an example of a carbohydrate used for energy storage and an example of a structural carbohydrate. What is different about the bonds connecting the monomers in the macromolecule?

energy storage – starch

Structural carbohydrate – cellulose

Different – starch has a glycosidic bonds. Cellulose has b glycosidic bonds.

Long chains of monosaccharides are called what? These can be in what two general forms?

polysaccharides

They can be in linear or branched form

What are the four primary functions of carbohydrates and cells? How does the structure of the polysaccharide support this function?

stores energy -plant store, carbs, and starches with a chain of glucose (branched) glycogen is made of chain of glucose and stores energy

Creates other bio molecules – creates carbon skeletons for amino acids and fatty acids and nucleic acids. ATP.

Structure – paul acids conform support structures. Use beta linkages to make cellular molecules hard to break apart because you need an enzyme to break it fungi makes chitin for their structure. Makes insoluble polymer. It's almost like mesh

Cellular identification – Polly saccharides can be refused to other biomolecules and facilitate intercellular communication

Lipids are primarily composed of what? This makes them insoluble or soluble in water?

lipids are primarily composed of hydrocarbon is making them insoluble in water

What are the three primary functional groups found within lipids

carboxyl, hydroxyl and phosphate

Lipids are super hydrophobic because of big carbon chains

What are the four types of lipids and indicate the three that contain fatty acids?

triglycerides waxes phospholipids and steroids

Triglycerides waxes and phospholipids contain fatty acids

Fatty acids are composed of a ____ group and a long ____ tail

fatty acids are composed of a carboxyl functional group (hydrophilic) and a long hydrophobic tail

Why are some fatty acid solids at room temperature and others are liquid?

Fatty acids are solid or liquid at room temperature based on how tightly their molecules can pack together

Saturated fatty acids are solids because of their straight structure, which gives them tight packing and a higher melting point

Unsaturated fatty acids are liquids because of their bent structure, which gives them loose packing any lower melting point

What is the structure of a triglyceride?

Energy can be stored in the form of triglycerides, then carbon like starch and glycogen what are the benefit benefits and cost of each method?

a triglyceride is a glycerol + three fatty acids

Triglycerides – insoluble in water, have a lighter weight, and less rapid accessibility, but they store more energy

Carbohydrates –soluble in water, heavier weight, and more rapid access to energy.

What are the parts that define wax?

Fatty acid and long chain alcohol connected by an ester bond

Why are waxes typically solid at room temperature?

Because of their long hydrocarbon tails. The chemical bonds and these tails are nonpolar and make them hydrophobic.

Common Biological functions of waxes

Structures (beehives), waterproofing (bird feathers), protection (earwax)

What are phospholipids made up of?

hydrophilic head – choline (+ charge), phosphate (- charge), and glycerol (ester linkaged to hydrophobic tail)

Hydrophobic – hydrocarbon chains

Why are phospholipids amphipathic?

because the head of the molecules hydrophilic and the tails are hydrophobic

With a membrane sheet, individual phospholipids can easily ____ and move____. however, they can only very rarely flip-flop to the other side of the bilayer because doing so requires an ____ and an input of ____ to overcome ____ interactions.

rotate

Laterally

Enzyme

Energy

Van der waal

What are the two primary function functions of phospholipids?

cell membrane structure, and cell signaling/communication

Phospholipid membranes are ___ permeable

selective

Chemicals have a tendency to become ____ distributed his solution overtime. When this occurs, it is in chemical ____. this process is called simple ____.

equally

Equilibrium

Diffusion

Characteristics of molecules that can easily cross the cell membrane

small – not a lot of space in between tails so you need to be tiny

Non-polar -hydrophobic and VDW interactions keep everything together so they need to be hydrophobic or they would just bond

What are the types of molecules that cannot cross the cell membrane on their own?

ions and large polar molecules

What is the structure of a generic steroid?

A generic steroid has a core chemical structure made of 17 carbon atoms arranged in four fused carbon rings

Rings A, B, and C: Three six-membered carbon rings.Ring D: One five-membered carbon ring attached to the end.

What are the two primary functions of steroids?

membrane fluidity/structured integrity and cell signaling

How does cholesterol maintain membrane integrity at high temperature?

restrict excessive movements of phospholipids

It fits into gaps because of unsaturated acid tails

It makes the membrane more robust

There's a decrease in fluidity in membrane

How does cholesterol support membrane fluidity at low temperatures?

asymmetrical shape prevents phospholipids from clustering and solidifying

It is not solid out low temperature

There's an increase in fluidity

glycolipids consist of ____ bound lipids of the cell surface

Carbohydrates

Combined with ___ and cholesterol, these molecules form excellent ____ that nerves used to propagate electrical signals rapid

proteins

Mylin sheath

A complete nucleotide contains what parts

base

Sugar (deoxyribose or ribose)

Phosphate

Structural components of DNA and RNA

DNA - (deoxyribose)has hydrogen at 2’C. nitrogenous bases are A-G C-T

RNA - (ribose) has hydroxyl group attached to 2’C. Nitrogenous spaces are A-G C-U

Distinguish between pyrimidines and purines

pyrimidine- 1 ring types found in DNA are C-T types found in RNA are C-U

Purine- 2 rings types found in DNA and RNA are A-G