Life 102 Final

K.Jeckel

Mass number

• Number of neutrons plus number of protons

Neutron

• Part of the nucleus

• no charge

Proton

• Part of the nucleus

• Positive charge

• dictates atomic number

Electron

• Part of the nucleus

• Negative charge

Properties of water

• Cohesion and Adhesion

• good solvent

• Low density as solid

• high specific heat

• Ionization of water

• Heat of vaporization

Hydrogen bond

• Forms between hydron and a more electronegative atom or group

Ionic Bond

• chemical bond in which there is a transfer of an electron from one atom to another

Polar Covalent bond

• type of covalent bond between two atoms where the electrons forming the bond are unequally distributed

nonpolar covalent bond

• electrons are equally shared

Hypotonic solution

• solution has lower concentration of dissolved particles than the cell

• Water diffuses into the cell

• the cell expands and bursts

Hypertonic solution

• Solution has a higher amount of solute than the cell

• Water moves out of the cell

• cell shrinks

Isotonic solution

• Solution has same solute concentration as cell

• water moves in and out equally

• no change

Ph

• measure of hydrogen ions in a solution

• Range: 0(acidic)-14(basicc)

• lower the pH the higher the hydrogen ion concentration

Saturated Fats

• single bond

• molecules are closely stacked together

• solid

Unsaturated fats

• double bond

• Molecules are further apart

• liquid

Phospholipid head

• Polar

• hydrophilic and on the outside of channel bilayer

Phospholipid tails

• nonpolar

• hydrophobic and on the inside of the channel bilayer

Exergonic reaction

• Energy released

• spontaneous

• negative delta G

Endergonic reaction

• Energy is added

• not spontaneous

• positive delta G

Pathway of Protein synthesis

• Nucleus → ER → golgi → cell membrane

Macromolecules

• Snythesized through polymerization

• Has two reactions:

  • Dehydration: removes a water molecule to add a monomer to a polymer making a longer polymer

  • Hydrolysis: adds a water molecule breaking a bond, polymer —> monomers

Activation energy

• amount of energy needed to start a chemical reaction

• lowered by enzymes

Enzymes

• Fit specific substrate

• speed up reactions

Competitive Inhibition (enzyme)

• inhibitor binds to the same site as the substrate

• prevents substrate from binding and inhibits reaction

Non-competitive inhibition (enzyme)

• binds to a different site (allosteric) on the enzyme

• changes enzyme conformation and enzyme cant bind to active site

Light Dependent Reaction

• Occur in the thylakoid membrane(grana)

• Inputs: Light. H2O, ADP, NADP+

• Outputs: O2, ATP, NADPH

Light Independent Reaction

• Occurs in the Stroma

• Needs the products of light reaction to occur

• Inputs:Co2, ATP. NADPH

• Outputs: GLucose, ADP, NADP+

Main stages of Cellular Respiration

1. Glycolysis

2. Pyruvate Oxidation

3. Citric Acid Cycle

4. Electron Transport Chain

Gycolosis

• Produces 2 ATP (2 invested, 4 made during)

• Creates 2 NADH that is passed to the electron transport chain

• Glucose is broken down to form 2 molecules of pyruvate

• does not require oxygen

• Location: Cytosol/cytoplasm

Pyruvate Oxidation

• Pyruvate is transformed to acetyl CoA

• occurs in Mitochondrial Matrix

• requires oxygen

• 2 Pyruvate —> 2CO2 + 2 NADH + 2 Acetyl CoA

Citric Acid Cycle

• The acetyl group is attatched to a four carbon oxaloacetate molecule to form a six carbon citrate molecule

• Through a series of steps the citrate is oxidized which realeases two carbon dioxide molecules for each acetyl group fed into the cycle

• The cycle can run continuously in the presence of sufficient reactants since the final product is the first reactant

• Location: Mitochondrial Matrix

• requires oxygen

• OVERALL REACTION: 2 acetyl groups + 6 NAD+ + 2 FAD + 2 ADP + 2 Pi —> 4 CO2 + 6 NADH + 2 FADH2 + 2 ATP

Electron Transport Chain

• Location: Inner Mitochondrial membrane

• Inputs: NADH, FADH2

• pumps the protins across the membrane to create a gradient that synthesizes ATP

• produces ATP and water

• requires oxygen

Mitosis

• new cells are born through the division of one cell into two

• identical daughter cells

• Asexual

• produces 2 diploid cells

Prophase (mitosis)

• chromatin condenses into chromosomes

• nuclear envelope breaks down

metaphase (mitosis)

• spindle fibers fully attach to centromere of each pair of sister chromatids

Anaphase (mitosis)

• sister chromatids separate (by shortening of spindle fibers)

• centromeres divide

Telophase

• Chromosomes reach opposite poles and begin to unravel

• nuclear envelopes form around the chromosomes

Cytokinesis

• final stage

• cytoplasm splits in two and the cell divides

Meiosis

• sexual

• 2 cell divisions

• produces 4 haploid cells (diff. DNA)

• Meiosis 1: separates homologues

• Meiosis 2: separates sister chromatids

Prophase 1 (Meiosis)

• Crossing over

• echange of genetic material between non sister chromatids of homologous chromosomes

Metaphase 1 (Meiosis)

• Independent assortment

  • Different genes and their alleles are inherited independently within sexually reproducing organisms

Homologous chromosomes

• one of a pair of chromosomes with the same gene sequence

• consists of one paternal and one maternal chromosome

Sister chromatids

• two identical copies of the same chromosome formed by DNA replication attached through centromere

Inheritance patterns

• different ways in which traits are passed from one generation to another

• determines by genotype of an individual

X-Linked inheritance

• pattern of inheritance in which a gene is located on the X chromosome

• has different effect on males and females

• Dominant: dominant gene carried on x chromosomes

• Recessive: recessive: gene carried on x chromosome and effects males more than females

Blood type Inheritance

• Determined by ABO gene on chromosome 9

• Child inherits one copy of the gene from each parent and can get: A, B, AB, or O depending on the combination of alleles

Mendel Inheritance

Three laws:

• In a heterozygous individual the dominant allele will be expressed, and the recessive allele will be hidden

• During Meiosis homologous pairs are separated and each gamete only receives one allele

• During meiosis homologous pairs separate randomly and independently of each other

Test Cross

• used to identify whether an organism exhibiting a dominant trait is homozygous or heterozygous for a specific allele

• the organism is crossed with an organism that is homozygous for the recessive trait and the offspring is examines

  • if the offspring is recessive the parent organism is heterozygous

Sexual Reproduction

• Meiosis

• combining genetic material from two parents

• offspring is genetically different from both parents

Asexual reproduction

• just mitosis

• copying genetic material from one parent

• offspring is genetically identical to the parent

• DNA replication

probability

• measurement tool that calculates the chance of likelihood of occurance of an event

• #of times something occurs/# of trials

Incomplete dominance

• neither allele is completely dominant

• blended appearance

• Ex: Red flower + White Flower = Pink Flower

Codominance

• phenotypes of both parents are simultaneously expressed in the same offspring organism

• Ex. Brown cow + White cow = Brown cow with white splotches

Pleiotropy

• single gene controlling or influencing multiple phenotypic traits

• Ex. sickle cell anemia causes multiple symptoms, only one of which is the actual sicle celled condition

Epistasis

• interaction between nonallelic genes at two or more loci resulting in one gene masking the phenotypic expression of another gene

• Ex. gene B influences the effect of gene A —> gene B is epistatic to gene A

Multiple alleles

• traits having more than one allele that can be found in the population

• Ex. Human blood type

DNA replication

Three steps:

• Initiation: assembly of replication fork at origin of replication

• Elongation: parental strands unwind and daughter strands are synthesized and the addition of bases by proteins

• Termination: the duplicated chromosomes separate from each other and now there are two identical copies of DNA

Enzymes involved in DNA replication

• DNA helicase: unwinds the DNA double helix

• RNA primase: builds on RNA primer

• DNA polymerase: matches and lays down nucleotides to build daughter strand

• DNA Ligase: joins the adjacent Okazaki fragments

Transcription in Prokaryotes

• Translation and transcription occur simultaneously in the cytoplasm

• RNA poly binds directly to promoter

• transcription makes mRNA (not processed)

• no introns

Transcription in Eukaryotes

• in nucleus

• DNA in nucleus, RNA travels in/out

• RNA poly binds to TATA box and transcription factors

• makes pre m-RNA —> RNA processing —> final mRNA

• Exons, introns (cut out)

Translation type of RNA

• mRNA are read as codons of three bases

• tRNA are responsible for bringing amino acids to the ribosome in the correct otder, ready for polypeptide assembly

Repressible operon

• usually functions in anabolic pathways synthesizing end products

• when end product is present in excess, cell allocates resources to other uses

• ex. trp operon

Inducible Operon

• usually functions in catabolic pathways digesting nutrients to simpler molecules

• produce enzymes only when nutrient is available

• Ex. Lac operon

Proto-oncogenes

• contribute to cancer

• involved in nornal cell growth and division

• if alters in certain ways they can contribute to cancer by allowing cells to grow and survive when they should not

Tumor Suppressor Genes

• involves in controlling cell growth and division

• if altered can cause genes to divide in an uncontrolled manner

DNA Repair Genes

• involved in fixing damaged DNA

• a mutation in this gene can cause the cells to become cancerous by causing the mutations to spread

Stem Cells

• can replicate themselves and create new cell types

• used by scientists to learn more about human biology and the development of therapeutics

• can show information on how diseases arise and suggest new strategies for therapy

totipotent

• capable of giving rise to any cell type including placental cells

• only embryonic cells within the first couple divisions after fertilization have this type of cell potency

Pluripotent

• Blastocyst stage

• can give rise to all of the cell types that make up the body except placental cells

Multipotent

• adult

• capable of giving rise to all cell types of a particular tissue or organ

Mutation

• an agent of change in evolution

• changes DNA and the only mutations that matter to evolution are the ones that can be passed down to offspring

Gene flow

• Agent of change in evolution

• movement of individuals and or genetic material from one population to another

Nonrandom Mating

• Agent of change in evolution

• if individuals nonrandomly mate with other individuals in the population choices can drive evolution in a population

  • influences alleles

Genetic Drift

• Agent of change in evolution

• in each generation some individulas may leave behind a few more decendants than other individuals

  • changes allele frequency

Natural Selection

• Mechanism for evolution

• individuals that are better adapted to their environment are more likely to produce offspring

Stabilizing Selection

• Selects against traits at the two extremes and selects for traits in the middle

• type of natural selection

Directional Selection

• type of natural selection

• occurs when there is selection for traits at one extreme and not the other

Disruptive Selection

• Type of natural selection

• occurs when traits at both extremes are selected for and traits in the middle are selected against

Divergent Evolution

• common ancestor

• changes in the environment cause them to adapt so they may look/act differently but they are still related

• homologous structures

Convergent Evolution

• No common ancestor

• organism have similar features and may act the same but are not related

• analogous structures

Homologous structures

• Anatomically similar but different functions

• ex. Whale flipper and bat wing

Analogous Structures

• Similar function but different structure

• Ex. Insect wing, and bird wing

Viruses

• require the presence of a host cell in order to multiply

• not considered alive

• infect a host cell and use the hosts replication processes to produce progeny virus particles

• infect all forms of organisms

Lytic cycle

• involves the reproduction of viruses using a host cell to manufacture more viruses

• the virus then burst out of the cell

lysogenic cycle

• involves incorporation of the viral genome into the host cell genome

• infects from within

Infection steps

• virion attatches to correct host cell

• the virus gains entrance into the cell

• the viral proteins and nucleic acid copies are manufactured by the cells machinery

• viruses are produced from the viral components

• newly formed virions are released from the cell

Gel electrophoresis

• DNA fragments from seven samples run on a gel, stained with a fluorescent dye, and viewed under UV light

PCR

• used to amplify specific sequences of DNA

How corona vaccines work

• scientists take part of the virus’s genetic code and turn it into a vaccine that is injected into the patient

• the vaccine enters the cells and tells them to produce the coronavirus spike protein

• if the patient later catches corona, the antibodies and T cells are triggered to fight the virus