BIOL1020

3 domains of life

Bacteria, archaea, eukarya

Endosymbiosis

The process through which prokaryotic cells adapt to become eukaryotic cells

Addition of sugar onto protein

Glycosylation

Addition of phosphate onto protein

Phosphorylation

Nucleoid

Region in prokaryotes in the cytoplasm where DNA is

Golgi apparatus

Receives newly made proteins

Transport proteins

Fimbriae

Projections from cell walls in bacteria

Involved in attachment to and movement on surfaces

Glycocalyx

Polysaccharide capsule that surrounds cell membrane

Protects bacteria from dehydration, allows adhesion to surfaces

Helps evade immune system

Function of cell membrane

Controls flow of molecules in and out of cell

Encloses and protects cell contents

Links to structures that provide cell shape/movement

Oligomers

Chains of 20 monomer units

Functions of carbohydrates

Store energy

Structural

Food source

Three types of cytoskeletons

Microtubules

Microfilaments

Intermediate filaments

Functions of proteins (8)

Structural

Enzymes

Defensive proteins

Transport

Hormonal

Receptor

Contractile and motor proteins

Metabolism

The sum total of all chemical reactions in an organism that sustain life

first and second law of thermodynamics

1. Energy in the universe is constant, not created nor destroyed

2. Every energy transfer or transformation increases entropy (disorder) of the universe

Exergonic

• Delta G

• Graph

DG is negative

Endergonic:

• DG

• Graph

Components of ATP

Stages of respiration

1. glycolysis

2. pyruvate oxidation

3. citric acid cycle

4. oxidative phosphorylation

   1. electron transport chain

   2. chemiosmosis

Theoretical and actual ATP yield

Theoretical = 32

Actual = 30 to 32

products per glucose molecule from glycolysis

• 2 ATP

• 2 NADH

• 2 H2O

• 2 pyruvate

products per pyruvate molecule from pyruvate oxidation

• 1 NADH

• NO ATP

• 1 CO2

• 1 acetyl CoA

products per acetyl-CoA molecule from citric acid cycle

• 2 CO2

• 3 NADH

• 1 FADH2

• 1 GTP (an equivalent of ATP)

Cell membrane links to

Cytoskeleton, extracellular matrix, cell wall, and cell-cell junctions

3 types of proteins in cytoskeleton

Microtubules, microfilaments, intermediate filaments

Microtubules shape, monomer, diameter, purpose

25nm diameter

helical hollow structure

tubulin monomer

Dynamic (can be rapidly formed and broken down)

Structural - help cell resist compression

Used in movement of whole cell, organelles within cell, and chromosomes in cell division

Microfilaments cc

7nm diameter

actin monomers

dynamic

supports shape and bears tension

endocytosis

spirally shape

Intermediate filaments shape, monomer, diameter, purpose

8-12nm

Coiled together

can be made of different monomers e.g. keratin

Structural framework of cell

Only in animal cells

Interphase stages

G1 (Gap 1)

S

G2

G1

Normal metabolic activity and cell growth

Synthesise proteins

S

DNA replicates

G2

Centrosomes appear (starting point for mitotic spindle)

Prophase

Chromatin condenses into chromosomes

Prometaphase

Nuclear membrane breaks down

Mitotic spindle attach to kinetochores

Metaphase

Mitotic spindle moves chromosomes to middle of cell

Anaphase

Sister chromatids separate

Cohesion protein at centromere degrades as chromosomes separate (mitotic spindle degrades centromere)

Telophase

Nuclear membrane forms

Checkpoints

G1 - does the cell have energy and resources to reproduce?

G2 - is DNA from S phase ok?

M - Are chromosomes attached to spindle?

GC as X H-bonds and AT has Y H-bonds

GC has 3

AT has 2

Purines have X rings, pyrimidines have Y rings

purines = 2

pyrimidines = 1

DNA polymerases

I - removes RNA primers

II - repairs DNA

III - adds nucleotides to growing strand

RNA polymerases

I - transcribes for rRNA

II - produces mRNA transcripts

III - transcribes for tRNA

sites in a ribosome

• A

  • tRNA tested for codon match

• P

  • Added to polypeptide chain

• E

  • tRNA is ejected into cytoplasm

electron transport chain in cellular respiration vs photosynthesis

• In contrast to mitochondrial electron transport chain

  • Water donates electrons to the chain and is oxidised to form oxygen

  • NADP+ is terminal electron acceptor

    • Reduced to  NADPH

  • Light energy drives electron transport

Light reaction

• Occurs in thylakoid

• Light absorbed by chlorophyl

• Electrons are excited and move through electron transport chain

• Water donates electrons and is oxidised into oxygen

  • Produces ATP and NADPH

Dark reaction

• Occurs in stroma

• ATP and electrons from NADPH are used to convert carbon dioxide into glucose

Direction of polypeptide chain synthesis

N-terminus → C-terminus

7 stages of viral life cycle

Attachment

Penetration

Uncoating

Transcription/translation

Genome replication

Assembly

Release

Retrovirus

Positive sense single stranded RNA that integrate themselves into DNA using reverse transcriptase

When glucose is not present, what happens to lac operon

Glucose = low means cyclic amp = high

Cyclic AMP binds to CAP and activates it

CAP binds to activator region on DNA

Increases transcription of lac operon (breaks down lactose)

Gene regulation in eukaryotes

• Chromatin remodelling

• Transcription

• RNA processing

• mRNA stability

• Translation

• Post-translational levels

Bacteria DNA modification

• Conjugation

  • Sharing F plasmid via sex pilus

• Transformation

  • Uptake of naked DNA into the bacterial cell

• Transduction

  • Virus (bacteriophage) transfers DNA from one bacteria to another

Missense vs nonsense mutation

Missense = change in amino acid

Nonsense = early stop codon

When does crossing over occur

Prophase I (pachytene)

When does independent assortment occur

Anaphase I

Plant lifecycle from zygote

Zygote

Sporophyte (2n)

meiosis

Spore

Gametophyte

fusion of gametes

Zygote

Egg making gametophyte

Archegonium

Sperm making gametophyte

antheridium

Temperatures for each stage of PCR

Denaturation - 96

Annealing - 55

Extension - 72

Human genome components largest to smallest

Repetitive DNA (transposable)

Repetitive DNA (nontransposable)

Introns

Unique noncoding

Regulatory

Protein coding

forward vs reverse primer

forward

• codes for strand written 3’ to 5’ left to right (antisense)

reverse

• for strand written 5’ to 3’ (sense)

is the phosphate on the 5’ or 3’ carbon

Alpha glucose and beta glucose diagram

How many electrons does FADH2 transport

2

Difference between DNA pol and RNA pol

DNA pol needs primer, RNA does not

DNA pol uses DNA nucleotides

Which carbon connects to the nitrogenous base, phosphate, and hydroxyl

N base = 1

Phosphate = 5

Hydroxyl = 3

deoxyribose sugar vs ribose sugar

Energy released for cellular respiration

-686kcal/mol

Cyclin levels

Begins production in S, increases through G2 and decreases after mitosis

Binds to CDK to form MPF, which phosphorylates mitosis proteins to bypass G2 checkpoint

oncogenes

genes that when activated, cause cancer

normal form - protooncogene

protooncogene normally promotes cell growth

Mutation in promoter region turns it into an oncogene (protooncogene is overexpressed)

Mendel’s first law and its exceptions

Law of segregation - alleles are independently inherited

Aneuploidy and polyploidy

Mendel’s second law of inheritance and its exceptions

Law of independent assortment

Genes assort independently

Parthenogenesis, haplodiploidy, sex-linked traits, mitochondrial DNA

cloning - recombinant plasmid is blue/white

white (lacZ gene is not intact)

Transposons vs retrotransposons

• Transposons

  • Directly transcribed and inserted into genome

• Retrotranspons

  • Translated into RNA

  • Reverse transcriptase synthesises DNA complimentary to RNA

  • Reverse transcriptase synthesises second DNA strand complementary to first DNA strand

  • Two strands are inserted into the genome