L1 Course Intro and Central Dogma

Lecture 1 August 27th

What are the 6 things that define living matter?

1. High degree of chemical and structural complexity

2. The capacity to extract, transform, and use energy from the environment

3. Defined functions for the organisms’ components and regulated interactions among them

4. A capacity to sense and respond to the environment

5. Capacity to self-replicate

6. Capacity to evolve

complex macromolecules

large organic molecules

need continuous input of energy so that they do not decay towards more disordered states & come to equilibrium with their surroundings

why are cells open systems?

they require the ability for

• input of energy sources and raw materials

• as well as the export of waste

lipid membrane function

serves as selective barrier for cell

allow cells to have a distinct intracellular environment different from its surroundings

Proteins

serve functions in cell

each serve a specific function

can be

• structural

• generate mvmnt

• sense/detect signals

• etc

enzymes

proteins capable of catalyzing reactions

(includes reactions needed to obtain and use energy from the environment)

where is genetic info stored?

in DNA

how can you qualify chemically DNA and RNA?

very simple — only 4 building blocks

nb. this structure helped convince scientists that genetic material was stored in DNA

central dogma of molecular biology

“DNA makes RNA, RNA makes proteins”

transcription

the copying of DNA into mRNA

Ribosomes

molecular machines that catalyze protein synthesis by reading mRNA to synthesize proteins using the genetic code. they are composed of proteins and rRNA (ribosomal RNA)

Translation

the synthesis of proteins through RNA

how many nucleotides are there and how many AAs

nucleotides: 4

AAs: 20

codon

3 consecutive nucleotides coding for an AA

tRNAn(transfer RNA )

a type of RNA molecule which is couples to an AA residue and pairs with the sequence in mRNA during translation to convert the sequence in codons into specific amino acids

what are the molecular principles that all life follows

• info flow is the same for all living beings

• we all use DNA as our genetic material

what can the analysis of DNA provide us with when it comes to life

• info on shared ancestry amongst spps

• estimate of the time when evolutionary events occured

• info on early events in life