BIO206 - Midterm #1

How is life on Earth composed of intricately organized chemical factories?

How is life on Earth composed of intricately organized chemical factories?

Take in matter from surroundings to generate copies

How is life on Earth variable?

Astonishing variety across different species

How is life on Earth consistent?

Astonishing consistency in fundamental mechanics

What are the 5 common characteristics of life?

Growth, metabolism, response to stimuli, movement, reproduction

What are cells?

Cells are the smallest unit of life and only arise from pre-existing cells

What’s an example of the huge diversity of size in life?

Typical rod-shaped bacteria is ~ 3 um, dolphin is ~ 3 million um / 3 m

What feature unifies life on Earth?

All organisms consist of cell(s) as either unicellular or multicellular organisms

What organisms are unicellular?

Bacteria, archaea, single-celled eukaryotes

What is microbiology?

The study of microscopic unicellular organisms

How does multicellular human complexity arise?

Single cell of 20 um diameter gives rise to 4 x 10^13 cells in a human body with an end-to-end of 4.5 x Earth’s circumference

What is the order of relative sizes of chemical structures?

Atoms, molecules, organelles, cells

What is 1 m equivalent to?

1000 mm, 10^6 um, 10^9 nm

What is 1 mm equivalent to?

1000 um

What is 1 um equivalent to?

1000 nm

What is the size range for atoms?

0.2 nm

What is the size range for molecules?

0.2 nm to 20 nm

What is the size range for organelles?

200 nm to 2 um

What is the size range for cells?

2 um to 0.2 mm (200 um)

What is the size range for the diameter of human hair?

20 um to 200 um (0.2 mm)

What is the typical size range for cells?

0.5 um to 20 um

What is resolution for an optical system?

The ability to tell apart two independent objects correctly. Small details will be lost in low resolution systems and the image would appear as a single, mixed blur.

What is the resolution of the naked human eye?

200 um = 0.2 mm

What is the capacity of the naked human eye to visualize cells?

Few specialized large cells

What is the resolution of a light microscope?

200 nm = 0.2 um

What is the capacity of a light microscope to visualize cells?

Most cells and some subcellular structures

What is the resolution of an electron microscope?

5 nm = 0.005 um

What is the capacity of an electron microscope to visualize cells?

Cells, subcellular structures and even some individual, large protein complexes

What is the physical description of a cell?

A sack made of lipid membranes, filled with aqueous solution containing various organic and inorganic molecules

What does a cell contain?

Macromolecules (nucleic acids, proteins, carbs, lipids), variety of other organic metabolites, inorganic ions, water, organelles (for eukaryotic cells)

Why does a cell need to orchestrate these compounds?

To grow, move, interact with the environment, consume energy, and reproduce

What is the Central Dogma?

The major principle which allows cells to take control of themselves. Genetic information written on DNA is expressed to produce a product which is used to control cellular activity (transcription and translation)

What is the result of transcription?

RNA synthesis

What is the result of translation?

Protein synthesis

When does DNA replication occur?

Copies of DNA is made when cell is ready to divide into two

What does ‘karyon’ mean?

Kernel / nut (nuclei looked like kernels to early scientists)

What does ‘pro’ mean?

Before

What does ‘eu’ mean?

True

What is a prokaryote?

Without kernels, “cells without defined nucleus”

What is a eukaryote?

With kernels, “cells with a true nucleus”

What are 5 characteristics of prokaryotes?

Lack membrane-bound nucleus, lack membrane-bound organelles, smaller than eukaryotes, mostly single-celled, consist of bacteria & archaea

What are 5 characteristics of eukaryotes?

Has membrane-bound nucleus, has other membrane-bound organelles that compartmentalize biochemical reactions, larger than prokaryotes, single/multicellular, consists of protists, fungi, plants, & animals

What are 8 prokaryotic structures?

Plasma membrane, cell wall, cytoplasm, nucleoid, ribosomes, internal membranes, inclusion bodies, flagella

What are 7 eukaryotic structures?

Nucleus, plasma membrane, endoplasmic reticulum, mitochondria, peroxisomes, lysosomes, ribosomes

What are the 3 domains of life?

Bacteria, archaea, eukaryotes

What are macromolecules?

The major structural, enzymatic, and regulatory component of all cells across the domains of life. Polymerized version of corresponding building block.

What is a polysaccharide?

Polymerized sugars

What is a polypeptide?

Polymerized amino acids

What is a nucleic acid?

Polymerized nucleotides

What are fats, lipids, and membranes?

Polymerized fatty acids

How do polysaccharides, polypeptides, and nucleic acids polymerize?

Covalent bonding

What are 2 functions of polysaccharides?

Cellular structures (ex. cellulose of tough bark), energy storage

What are 2 functions of proteins (functional, folded versions of polypeptides)?

Catalysts, cellular structures, etc.

What are 2 functions of nucleic acids?

Storage of genetic material, catalysts

How do fatty acids polymerize compared to the other macromolecules?

Hydrophobic/hydrophilic interactions, not by covalent bonding

What is the structure of a fatty acid?

Polar hydrophilic head connected to a non-polar hydrophobic tail

What is a polar hydrophilic head?

Interacts with other polar molecules such as water

What is a non-polar hydrophobic tail?

Interacts with other hydrophobic molecules

What is a phospholipid bilayer?

In an aqueous environment, fatty acids form a double-layered structure where heads line up facing water while tails form the hydrophobic core and interact with themselves

Where are phospholipid bilayers found?

Plasma membrane, which defines the boundaries of a cell

Where might a phospholipid monolayer be found?

Hydrophilic heads facing water, hydrophobic tails facing (non-polar) oil

What is Streptococcus pneumoniae?

Bacterial pathogen where smooth (S) strain causes pneumonia and rough (R) strain does not cause pneumonia

How does S. pneumoniae show the genetic information is stored in DNA?

R strain which receives extracted and purified S strain DNA gets converted to an S strain, whereas R strain which receives other macromolecules does not get converted. So, the molecule that carries the heritable information is DNA

How does DNA allow for the storage and inheritance of genetic information?

DNA replication / synthesis

How does DNA allow for processing genetic information to build proteins?

Transcription (RNA synthesis) and translation (protein synthesis)

How does cellular compartmentalization in eukaryotes affect the Central Dogma?

mRNA needs to cross the nuclear membrane via nuclear pore from DNA inside the nucleus to ribosomes in the cytoplasm

What is the genome?

Total genetic information carried by a cell/organism, mostly consisting of DNA

What are 5 types of nucleotides?

DNA, RNA, ATP, GTP, cAMP

What is the function of DNA nucleotides (deoxyribonucleotides)?

Storage of genetic information

What are the 2 functions of RNA nucleotides (ribonucleotides)?

Carrier of genetic information + structural components of tRNA, ribosomes, spliceosomes, etc.

What are the 3 functions of ATP & GTP?

Energy metabolism (performing biochemical work), building blocks of RNA, can turn into other metabolites such as cyclic AMP

What is the function of second messengers such as cAMP?

Cellular signalling

What is DNA?

A linear polymer of deoxyribonucleotides

What is RNA?

A linear polymer of ribonucleotides

What are the 3 components of a nucleotide?

Phosphate + pentose sugar (5C) + nitrogenous base

What are 3 nucleotide variations?

Contains up to 3 phosphates, 5 types of nitrogenous bases, 2 types of pentose sugars

What are the names of different phosphate groups on nucleotides?

Monophosphate (ex. deoxyadenosine-5’-monophosphate / dAMP), diphosphate (ex. deoxyadenosine-5’-diphosphate / dADP), triphosphate (deoxyadenosine-5’-triphosphate / dATP), no phosphate group in name for nucleosides

What bonds phosphate groups of a nucleotide together?

Phosphoanhydride bonds

What are pyrimidines?

Nitrogenous bases with single ring (longer name, smaller structure)

What are purines?

Nitrogenous bases with double ring (shorter name, larger structure)

What are the 3 types of pyrimidines?

Thymine (T), cytosine (C), uracil (U)

What are the 2 types of purines?

Adenine (A), guanine (G)

What is the molecular structure of a pyrimidine (for 3 common pyrimidine of central dogma)?

Six-atom ring, two nitrogens at positions 1 & 3, carbon 2 always connected to oxygen with double bond, carbon 4 always connected to extra atom outside ring

What is the molecular structure of a purine (for 2 common purines of central dogma)?

Nine atoms constituting two rings (hexagon + pentagon), nitrogen in the larger ring further away from smaller ring is nitrogen 1, nitrogen in the smaller ring connected to carbon 5 is nitrogen 7, nitrogen in smaller ring without a double bond is nitrogen 9

What are the 2 types of pentose (5-carbon) sugars?

Ribose or deoxyribose

What is a nucleoside?

Pentose sugar + nitrogenous base (lacks phosphate)

What is ribose?

Has OH group at #2 carbon, building block of ribonucleic acid

What is 2-deoxyribose?

Lacks OH group at #2 carbon, building block of deoxyribonucleic acid

How are the carbons and nitrogens of nitrogenous bases and pentose sugars numbered?

Purines numbered 1-9. Pyrimidines numbered 1-6, ribose sugars numbered 1’-5’ (noted with prime to distinguish from numbers of nitrogenous bases)

What links the sugar and nitrogenous base in a nucleotide?

N-glycosidic bond, where the bond-forming atoms are consistent

What atoms form the N-glycosidic bond in purines?

Nitrogen 9 is connected to 1’ carbon of ribose sugar

What atoms form the N-glycosidic bond in pyrimidines?

Nitrogen 1 is connected to 1’ carbon of ribose sugar

In the nucleotide adenosine triphosphate (ATP), where are the phosphates attached to?

5’ carbon of ribose sugar

What is the nucleoside for adenine?

Adenosine (A)

What is the nucleoside for guanine?

Guanosine (G)

What is the nucleoside for cytosine?

Cytidine (C)

What is the nucleoside for uracil?

Uridine (U)

What is the nucleoside for thymine?

Thymidine (T)

What is the nomenclature for the name of a nucleotide?

Name of nucleoside + number of phosphates

How are nucleotides abbreviated?

Three capital letters (nucleoside + MP, DP, TP)

How is the sugar of a nucleotide denoted in the name?

Just the name of the nucleoside if ribose, include “deoxy-” prefix to front of nucleoside name if deoxyribose (ex. deoxyadenosine monophosphate is dAMP)