IB Biology I Sem 2 Final

is water polar or non-polar? why?

polar because there is an uneven distribution of electrons between oxygen and hydrogen atoms

what are the 4 important properties of water based on hydrogen bonding?

1. cohesion

2. adhesion

3. capillary action

4. solvent properties

what is cohesion?

an attraction between molecules of the same substance

what is adhesion?

attraction between molecules of different substances

what is capillary action?

the attraction of the surface of a liquid to the surface of a solid

what are solvent properties?

Water dissolves polar and ionic substances

what are the possible origins of water and why does it stay?

- asteroids collided with earth

- stays because of gravity and earth is the perfect distance from the sun

Name the function, monomer, and an example for carbohydrates, lipids, and proteins (SHORT ANSWER)

CARBOHYDRATES

- function: short-term energy storage and structure

- monomer: monosaccharides

- ex: glucose

LIPIDS

- function: long term energy storage

- monomer: fatty acids

- ex: oil

PROTEINS

- function: catalyze reactions

- monomer: amino acids

- ex: hemoglobin

What are the characteristics of saturated fatty acids?

- carbons are carrying as many hydrogen atoms as they can

- solid at room temp

What are the characteristics of monounsaturated fatty acids?

- one double bond in the chain of hydrocarbons

- liquid at room temp

What are the characteristics of polyunsaturated fatty acids?

- have at least 2 double bonds in the carbon chain

- liquid at room temp

What are the characteristics of cis fatty acids?

- liquid at room temp

- low melting point

- hydrogens on the same side of the carbon double bond

What are the characteristics of trans fatty acids?

- higher melting point

- solid at room temp

- hydrogens on different sides of the carbon double bond

Why is carbon an important element for life?

allows for the formation of diverse compounds that life is based on

Peptide bonds connect_______ ________ to form ________ using a ________________ ____________

amino acids - proteins -condensation reaction

draw the basic structure of an amino acid (SHORT ANSWER)

what is the effect of temperature on the action of the enzyme?

as temperature increases, enzyme activity speeds up

what is the effect of pH on the action of the enzyme?

enzymes have an optimal pH where activity is the highest

what happens to the enzyme activity when the substrate or enzyme concentration increases?

the substrate-active site collisions happen more frequently and the rate of reaction increases

Explain the relationship between the structure of the active site, enzyme-substrate specificity, and denaturation

- the shape and chemical properties of the active site allow substrate molecules to bind

- when the enzyme denatures it changes the shape of the protein which prevents the substrate from binding

what is the effect on a graph of the relationship between temperature and enzyme activity?

increases, peaks, then decreases

what is the effect on a graph of the relationship between pH and enzyme activity?

increases, peaks, and the, decreases

what is the effect on a graph of the relationship between substrate concentration and enzyme activity?

increases then plateaus

what is competitive inhibition?

An inhibitor competes with the substrate for binding to the active site

what is noncompetitive inhibition?

inhibitor binds at a site different from substrate, the allosteric site

List evidence for the last universal common ancestor and where it evolved (SHORT ANSWER)

the genetic code is the same for all species and it evolved in the vicinity of hydrothermal vents

what is the cell theory?

All living things are made up of cells, cells are the most basic units of life, new cells are produced from existing cells

compare and contrast eukaryotes and prokaryotes

eukaryotes - large, complex, nucleus

prokaryotes - small, simple, no nucleus

both have DNA

what are the differences between plant and animal cells?

plants have a cell wall, chloroplasts, and a large vacuole

function of the plasma membrane

controls the entry and exit of substances

function of cytoplasm

where metabolism and enzyme reactions occur

function of free ribosomes

proteins that stay in cytoplasm or enter the nucleus

function of ribosomes on rough er

make proteins that will leave the cell

function of the nucleus

holds the cell's chromosomes

function of the mitochondria

carries out aerobic respiration to make ATP energy

function of the rough er

transport proteins to the golgi apparatus

function of the smooth er

allows molecules to move throughout the cell

function of the golgi apparatus

processes and packages substances for export from the cell

function of the vacuoles

storage area

function of the lysosomes

contains strong enzymes used for digestion

function of the cholorplast

produces glucose through photosynthesis

function of the cytoskeleton

gives the cell its shape

function of the microtubules

moving chromosomes during cell division

function of the centrioles

anchor points for microtubules during cell division

function of the cillia

hair-like structures used to move the cell

function of the flagella

whip-like structure that allows a cell to move

draw a lipid bilayer of the plasma membrane (SHORT ANSWER)

polar (hydrophilic) head and two non-polar (hydrophobic) tails

define active transport and give an example

movement of particles against the concentration gradient using ATP energy - ex: pump proteins

define passive transport and give an example

movement of particles with the concentration gradient (no ATP needed) - ex: osmosis, facilitated diffusion

what does it mean to say a cell is HYPERtonic?

water is moving out of the cell - cell shrivels up

what does it mean to call a cell HYPOtonic?

water is moving into the cell - cell swells up

what does it mean to call a cell isotonic?

water is moving equally in and out of the cell - cell is normal sized

what is solvation?

a solute dissolving in water

what are the steps of the cell cycle?

G1, S, G2, Mitosis

what happens during the G1 phase of the cell cycle?

cell growth

what happens during the S phase of the cell cycle?

DNA replication

what happens during the G2 phase of the cell cycle?

cell growth and preparation for mitosis

what is crossing over and when does it occur?

The exchange of genes between homologous chromosomes during prophase I

what are the steps of mitosis?

prophase, metaphase, anaphase, telophase

what happens during prophase?

chromosomes condense

what happens during metaphase?

Chromosomes line up in the middle of the cell

what happens during anaphase?

sister chromatids separate

what happens during telophase?

new nuclear membranes form

what is the purpose of mitosis?

cell reproduction

Label the steps of mitosis and cytokinesis (SHORT ANSWER)

prometaphase not needed

what are the steps of meiosis?

Prophase 1, Metaphase 1, Anaphase 1, Telophase 1, Prophase 2, Metaphase 2, Anaphase 2, Telophase 2

what is the purpose of meiosis?

produce gametes for sexual reproduction

how many chromosomes are present after mitosis?

46

how many chromosomes are present after meiosis?

23

State and draw the structure of nucleotides (SHORT ANSWER)

sugar, phosphate, base

what is the shape of DNA called?

double helix

what are complementary base pairings?

Adenine + Thymine, Cytosine + Guanine

how are DNA and RNA similar?

They are both nucleic acids

how are DNA and RNA different?

DNA is double stranded, has thymine, and is deoxyribose sugar

RNA is single stranded, has uracil, and is ribose sugar

is DNA replication conservative or semi-conservative?

semi-conservative

what are the steps of DNA replication?

1. original strand of DNA is unzipped by an enzyme that breaks the hydrogen bonds between the bases.

2. Free nucleotides attach to their complementary base

3. Another type of enzyme connects these nucleotides into a chain

4. This process continues until the entire strand of DNA has been unzipped and copied.

- always in 5'-3' direction

what are the steps of the polymerase chain reaction (PCR)?

Melting, Annealing, Elongation

what is gel electrophoresis?

lab method that separates DNA by length

what is transcription?

The process of making RNA from DNA

what are the steps of transcription?

- promoter (section of DNA) starts the process and allows transcription factors to bind

- RNA polymerase binds to DNA and unwinds into 2 strands

- RNA polymerase moves along the template strand adding nucleotides

what is translation?

the decoding of an mRNA message into a protein

what are the steps of translation?

initiation, elongation, translocation, termination

what is the complementary base pairing of DNA to RNA? (SHORT ANSWER)

A-U, T-A, G-C, C-G

what is tRNA?

transfer RNA - transfers one specific amino acid to the ribosome

what is rRNA?

ribosomal RNA - combines with proteins to make the ribosomes where proteins will be make

what is mRNA?

messenger RNA - carries genetic information in DNA from nucleus to cytoplasm

what are anticodons?

Three bases on tRNA that match to codons on mRNA

what are codons?

mRNA triplets that code for an amino acid

what is splicing?

Removal of introns and joining of exons.

what is a haploid cell?

cell with half the number of chromosomes (23)

what is a diploid cell?

cell that has both sets of chromosomes (46)

what are homologous chromosomes?

two genetically similar chromosomes, one from each parent

what does homozygous mean?

two of the same alleles

what does heterozygous mean?

two different alleles

what is phenotype?

physical characteristics of an organism

what is genotype?

genetic makeup of an organism

what is a gene?

segment of DNA that codes for a protein

what is an allele?

an alternative version of a gene

what is a recessive trait?

A trait that will only appear in the offspring if both parents give it

what is a dominant trait?

a trait that will appear in the offspring if one of the parents contributes it