BIO 198 - Exam 1

bio exam 1

what are the characterisitcs of living systems

celluar organization, ordered complexity, sensitivity

growth/development/reproduction, energy utilization, homeostasis, evolutionary adaption

Define an element based on its composition.

It is any substance that cannot be broken down to any other substance by ordinary chemical means. An element has the same number of protons as it's atomic number and atoms.

describe the relationship between atomic structure and chemical properties

the number of protons (atomic number) determines the chemical properties of the atom (element type)

where are electrons found in an atom

found in the orbitals surrounding the nucleus

what are the important elements found in living systems?

SPONCH

which elements are likely to form ions?

ion is a charged particle. they lost or gained an electron. ​see how many valence electrons they have if they would need one to be stable or not on their outermost shell

how can molecules be built from atoms joined by covalent bonds?

Not equally sharing electrons and one is more electromagnetic than the other

what is a polar covalent bond?

A polar covalent bond is when one atom is more electronegative and the atoms don't share the electrons equally

what is a nonpolar covalent bond?

a nonpolar covalent bond is when they share the electrons equally

What does cohesion mean?

water molecules sticking to one another by hydrogen bonding

What does adhesion mean?

attraction between water molecules and other molecules around it that aren't water by hydrogen bonding

how does hydrogen bonding affect the properties of water?

water:

• has a high specific heat,

• has a high heat of vaporization

• solid water is less dense than liquid water

• is a good solvent

• organizes nonpolar molecules

• and can form ions

define an acid

any substance that dissociates in water to increase the (H+) and lower the pH.

define a base

a substance that combines with H+ when dissolved in water, and thus lowers the 0h-.

define the pH scale

a more convenient way to express hydrogen ion concentration of a solution. The scale defines pH, which stands for "partial hyrogen", as the negative logarithm of the hydrogen ion concentration in the solution.

Relate changes in pH to changes in ( H+).

Because the pH scale is logarithmic, a difference of 1 on the scale represents a 10-fold change in (H+). A solution with a pH of 4 therefore has 10 times the H+ of a solution with a pH of 5 and 100 times the H+ of a solution with a pH of 6.
On a pH scale, the H+ concentration increases as the pH value decreases.
*Low pH represents high H+ concentration.

Describe the relationship between functional groups and macromolecules.

Functional groups add chemical properties and are found in macromolecules.

what functional group is this?

hydroxyl: found in carbs & nucleic acids; polar & hydrophilic

what functional group is this?

carbonyl: found in carbs & nucleic acids; hydrophilic

what functional group is this?

amino: found in proteins & nucleic acids; charged & accept H+ ion => basic

what functional group is this?

carboxyl: found in lipids & proteins; charged & acidic

what functional group is this?

phosphate: found in nucleic acids; charged

what functional group is this?

methyl: found in nucleic acids; hydrophobic & nonpolar

what functional group is this?

sulfhydryl: found in proteins; hydrophilic & polar

Recognize the different kinds of isomers

structural isomers- differences in the actual structure of their carbon skeleton.

strereoisomers- has the same skeleton but differ in how the groups attached to this skeleton like a mirror.

List the different kinds of biological macromolecules.

Carbohydrates, Nucleic Acids, Proteins, and Lipids

Describe the structure of simple sugars with three to six carbons.

The empirical formula of six-carbon is : C6H1206 OR CH2O6

six-carbon sugars can exist in a straight chain form, but dissolved in water they almost form rings.

play important role in energy storage

Relate the structure of polysaccharides to their functions.

Polysaccharides provide energy storage and structural components.

Polymers made up monosaccharides that are joined by dehydration reactions.

starch-glucose molecules (energy storage) long chains

celluose-chitin (structural support) strong and rigid

Describe the structure of nucleotides.

Nucleotide include three components: a five-carbon sugar or pentose, a phosphate group (-PO4), and an nitrogenous base.

dehydration synthesis

formation of large molecules by the removal of water

hydrolysis

breakdown of large molecules by the addition of water

ratio of carbon:hydrogen:oxygen

1:2:1

Contrast the structures of DNA and RNA.

DNA- double helix, use thymine among its nitrogenous bases. deoxyribose sugar used.
RNA- usually single-stranded, uses ribose in the sugar-phosphate backbone, and uses uracil in place of thymine.

Discuss the functions of DNA and RNA.

DNA:

• encodes information for amino acid sequence of proteins

RNA:

• uses information in DNA to specify sequence of amino acids in proteins

what is the function of mRNA?

carries info out of the nucleus to be translated in the cytoplasm

what is the function of tRNA?

brings the amino acids to the site of protein synthesis at the ribosome

what is the function of rRNA?

is a structural component and catalytic component of the ribosome

Recognize other nucleotides involved in energy metabolism.

Adenosine triphosphate (ATP)

• primary energy currency of the cell

Nicotinamide adenine dinucleotide (NAD+)
Flavin adenine dinucleotide (FAD)

• electron carriers for many cellular reactions

what are the components of a nucleotide?

sugar (carbohydrate) + phosphate + nitrogenous base

What are the different nitrogenous bases?

purines and pyrimidines

What bases fall into the purine category?

Adenine (A) and Guanine (G) [AG=silver is pur(e) = 2 “silver” rings]

What bases all into the pyrimidine category?

Cytosine (C), Thymine (T), and Uracil (U)

what are protein functions?

enzyme catalysis, defense, transport, support, motion, regulation, storage

Describe the possible levels of protein structure.

Primary structure
Secondary structure
Tertiary structure
Quaternary structure

What bonds occur between the sugars and phosphates in DNA and RNA?

phosphodiester bonds

What bonds occur between the two paired bases in DNA?

Hydrogen bonds

what are the components of an amino acid?

amino group, carboxyl group, single hydrogen, central carbon atom, variable R group/side chain

why is methionine (Met) important?

it’s always the first amino acid of a protein (AUG)

why is cysteine (Cys) important?

it forms disulfide bridges to help keep proteins shape

What are disulfide bridges

Covalent bonds between sulfurs in sulfhydryls
- Anchors 3-D shape of tertiary structure

What are peptide bonds?

covalent bonds between amino acids in proteins; during protein synthesis, amino acids are joined by dehydration synthesis

What is unique about the primary structure?

The sequence of amino acids in a polypeptide chain, similar to the sequence of letters that spell out a specific word

What is based on a protein's shape?

its function

What is unique about the secondary structure?

The line of amino acids begins to bend, and hydrogen bonds are created between amino acids

What are the two most common patterns of the secondary structure?

twist (alpha helices) or zig-zag (beta sheet)

What are motifs?

patterns of secondary structure

What are domains?

independent folding units in a 3D structure of a protein
- individual domain shave a unique function that it gives to the protein

What are the possible bonds in the tertiary structure?

hydrophobic interactions, H bonds (W), ionic bonds (M), and disulfide bridges (covalent bonds -S)

What is unique about the tertiary structure?

it is the complex three-dimensional shape formed by the multiple twists and bends in the polypeptide chain
- bonds between R-groups

What is unique about the quaternary structure?

Two or more polypeptide chains held together by bonds between the amino acids on different chains (subunits)

what is denaturation?

when a protein loses structure and function; when a protein unfolds

What causes proteins to denature?

extreme change in heat, pH, or ionic concentration of solution

dissociation

when subunits leave the protein without losing their tertiary structure

What do chaperone proteins do?

help with correct structure formation (helps with folding, keeps different parts from binding incorrectly, keeps things from unfolding, refolds)

Describe the structures of triglycerides.

A fat molecule containing three fatty acids combined with a glycerol.

Explain how fats function as energy-storage molecules.

Most fats contain over 40 carbon atoms. The ratio of energy storing C-H bonds in fats is more than twice that of carbohydrates, making fats much more efficient for storing energy

Apply knowledge of the structure of phospholipids to the formation of membranes.

The phospholipid bilayer creates a paradoxical effect with it being hydrophobic and hydrophilic; semipermable

What are lipids?

insoluble molecules

what are micelles?

lipid molecules that orient with polar (hydrophilic) head toward the water and nonpolar (hydrophobic) tails away from water

examples of lipids

fats, oils, waxes, steroids, and some vitamins (vitamin D)

What are saturated fats?

lipids with single bonds between carbon atoms
- maximum number of Hydrogen atoms
- solid fats

What are unsaturated fats?

Long hydrocarbon chains that have single bonds, except for one double bond in the middle, and are good fats
- make it harder for lipids to pack together by adding kinks
- reduced number of H atoms
- shorter shelf life

What are trans fats?

The type of fat produced when manufacturers add hydrogen to the fat molecules in vegetable oils
- act more like saturated fats
- longer shelf life

Categorize structural and functional similarities in cells.

What all cells have in common:
1) A nucleoid or nucleus where genetic material is located 2) cytoplasm 3) ribosomes to make proteins 4) a plasma membrane

when were cells discovered and by who?

in 1665 by Robert Hooke; he discovered cork cells

who observed the first living cells?

Anton van Leeuwenhoek; he discovered microtubules

who proposed the Cell Theory?

Schleiden and Schwann

Discuss Cell Theory.

Cell theory was proposed to explain the observation that all organisms are composed of cells.
Three Principles
1) All organisms are composed of one or more cells, and the life processes of metabolism and heredity occur within these cells.
2) Cells are the smallest living things and basic units of life.
3) Cell arise only by division of a previously existing cell.

Describe the factors that limit cell size.

Because of the rate of diffusion in and out. 1) the surface area available for diffusion 2) temperature 3) concentration gradient of diffusing substance 4) the distance over which diffusion must occur.

what is surface area to volume ratio?

as a cells size increases, its volume increases much more rapidly than its surface area

Categorize structural and functional similarities in cells.

What all cells have in common:
1) A nucleoid or nucleus where genetic material is located 2) cytoplasm 3) ribosomes to make proteins 4) a plasma membrane

Describe the organization of prokaryotic cells.

Prokaryotic cells has a simple organization, and they are small and consist of cytoplasm surrounded by a plasma membrane and encased within a rigid cell wall.

Distinguish between bacterial and archaeal cell types.

Bacterial wall has peptidoglycan, but archaeal lacks it.

Compare the organization of eukaryotic and prokaryotic cells.

Eukaryotic cells are more complex and prokaryotic is simpler.

Discuss the role of the nucleus in eukaryotic cells

The nucleus in eukaryotic cells has the role as the information center or repository of the genetic info.

Describe the role of ribosomes in protein synthesis.

Ribosomes are the cell's protein synthesis machinery where two subunits join.

Identify the different parts of the endomembrane system.

Rough endoplasmic reticulum and Smooth endoplasmic reticulum

Contrast the different functions of internal membranes and compartments.

RER is the site of making proteins.
SER store lipids, sends things to whatever part of the cell it needs to go, stores Ca+, and modifies foreign substances.

Describe the structure of mitochondria and chloroplasts

Both are surrounded by double membranes, and both contain their own DNA and protein synthesis machinery.

Compare the function of mitochondria and chloroplasts

Both are involved in energy metabolism. Mitochondria metabolizes sugar to make ATP. chloroplasts uses light to generate ATP and sugars

Explain the probable origin of the mitochondria and the chloroplasts

Both are thought to have arisen by endosymbiosis when a free living cell is taken up but not digested (endosymbiotic theory)

Illustrate the role of microtubules in intracellular transport

Microtubules organize the cytoplasm and are responsible for moving materials within the cell.

Describe how cells move.

An arrangement of actin filaments within the cytoplasm allow cells to crawl. Flagella and cilia also aid movement.

what is the nucleolus?

the region where ribosomal RNA synthesis takes place

what is the nuclear envelope?

it has 2 phospholipid bilayers & it has nuclear pores that control the passage in and out

what is the nuclear lamina?

it is composed of intermediate filament fibers that give the nucleus shape and is involved in deconstruction and reconstruction during the cell cycle

what is chromatin?

it is chromosomes + a protein

what is the inner region of the endoplasmic reticulum called?

cisternal space/lumen

what is the golgi apparatus?

it functions in sorting, packaging and distribution of molecules synthesized at one location and used at another within the cell or even outside of it; has cis (closet to ER, receiving) and trans (where things exit) faces

what do vesicles do in the golgi apparatus?

transport molecules to their destination