Guided notes covering material from Topic 2.3 of the updated IB Biology syllabus for 2016 exams. Notes sequence and prompts are based on the Oxford IB Biology textbook by Allott and Mindorff.
Guided notes covering material from Topic 2.3 of the updated IB Biology syllabus for 2016 exams. Notes sequence and prompts are based on the Oxford IB Biology textbook by Allott and Mindorff.
Different carbohydrate metabolism pathways by microbesTRIDIP BORUAH
Carbohydrate is the major source of energy for a variety of microbes. Here are some significant metabolic pathways by which microorganisms utilize carbohydrates
Guided notes covering material from Topics 2.4 and 7.3 of the updated IB Biology syllabus for 2016 exams. Notes sequence and prompts are based on the Oxford IB Biology textbook by Allott and Mindorff.
Introducing the Evolutionary Cell Memory (ECM) Hypothesis banafsheh61
This research study has gone through more than 34 sample tumors in Violet Cancer Institute (VCI) to find the cancer
cells’ resemblances to the primitive eukaryote cells in 3.5 billion years ago before the entrance of the mitochondria
into the eukaryote cells as endosymbionts. Nearly all the samples showed that the mitochondria inside the cells were
not working properly. Their cristae were damaged or the mitochondria did not work or better said “shut down”
inside the cancer cells. This study introduces a new hypothesis called the Evolutionary Cell Memory (ECM) based on
the Lamarckian Evolutionary Hypothesis and the Evolutionary Metabolic Hypothesis of Cancer introduced by the
Somayeh Zaminpira and Sorush Niknamian in 2017.
Guided notes covering material from Topic 2.1 of the updated IB Biology syllabus for 2016 exams. Notes sequence and prompts are based on the Oxford IB Biology textbook by Allott and Mindorff.
Different carbohydrate metabolism pathways by microbesTRIDIP BORUAH
Carbohydrate is the major source of energy for a variety of microbes. Here are some significant metabolic pathways by which microorganisms utilize carbohydrates
Guided notes covering material from Topics 2.4 and 7.3 of the updated IB Biology syllabus for 2016 exams. Notes sequence and prompts are based on the Oxford IB Biology textbook by Allott and Mindorff.
Introducing the Evolutionary Cell Memory (ECM) Hypothesis banafsheh61
This research study has gone through more than 34 sample tumors in Violet Cancer Institute (VCI) to find the cancer
cells’ resemblances to the primitive eukaryote cells in 3.5 billion years ago before the entrance of the mitochondria
into the eukaryote cells as endosymbionts. Nearly all the samples showed that the mitochondria inside the cells were
not working properly. Their cristae were damaged or the mitochondria did not work or better said “shut down”
inside the cancer cells. This study introduces a new hypothesis called the Evolutionary Cell Memory (ECM) based on
the Lamarckian Evolutionary Hypothesis and the Evolutionary Metabolic Hypothesis of Cancer introduced by the
Somayeh Zaminpira and Sorush Niknamian in 2017.
Guided notes covering material from Topic 2.1 of the updated IB Biology syllabus for 2016 exams. Notes sequence and prompts are based on the Oxford IB Biology textbook by Allott and Mindorff.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
2. The official IB Diploma Biology guide
Essential idea: Water is the medium of life
https://ibpublishing.ibo.org/server2/rest/app/tsm.xql?doc=d_4_biolo_gui_1402_1_e&part=8&c
hapter=1
3. An essential molecule
Approximately 71 percent of the Earth's surface is water-covered, and the oceans
hold about 96.5 percent of the water of the earth and its saline.
Each day, 1,170 km3 of water evaporate or transpire into the atmosphere.
About 12,900 km3of water, mostly in the form of water vapor, is in the atmosphere
at any one time
Up to 60% of the human adult body is water
The brain and heart are composed of 73% water, and the lungs are about 83% water
Generally, an adult male needs about 3 liters per day while an adult female needs
about 2.2 liters per day
http://water.usgs.gov/edu/earthhowmuch.html
http://water.usgs.gov/edu/propertyyou.html
4. The structure of the water molecule
Water molecules are polar and hydrogen bonds form between them.
A water molecule consists of an oxygen atom covalently bonded
with two hydrogen atoms
Oxygen having a higher electronegativity than hydrogen attracts the
electrons more strongly and hence, the electron pairs are placed
closer to the oxygen nucleus than to the hydrogen nucleus
As a result of that the oxygen atom has a partial positive charge (+δ)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1299179/
5. Carbon compounds
Carbon atoms can form four covalent bonds allowing a diversity of stable compounds to exist.
C
6 2
4
Carbon
12.0107
Carbon is the 15th most abundant element on earth but can be used to create
a diverse group of compounds which contribute to a diverse palette of
structures and functions.
Chemical properties of carbon
• May create four covalent bonds (strongest bonds) with other atoms.
Remember that covalent bonds result from the sharing of pairs of
electrons by two adjacent atoms. Look at the CH4 molecule
https://upload.wikimedia.org/wikipedia/c
ommons/thumb/2/29/Electron_shell_006
_Carbon.svg/558px-
Electron_shell_006_Carbon.svg.png
Carbon electron configuration
Carbon in the
period table
https://upload.wikimedia.org/wikipedia/commons/thumb/1/17/Covale
nt.svg/334px-Covalent.svg.png
covalent bond Biological significance
• The large number of covalent bonds
leads to the development of complex
structures either with other carbon
atoms (carbon chains)
https://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Linoleic_acid_
shorthand_formula.PNG/800px-Linoleic_acid_shorthand_formula.PNG
• or with other chemical elements
https://upload.wikimedia.org/wiki
pedia/commons/thumb/8/88/D-
Phenylalanine.svg/228px-D-
Phenylalanine.svg.png
Bonds between carbon
atoms and other
chemical elements may
be single or double or
even triple
https://qph.ec.quoracdn.net/main-qimg-
d3f0d78f8981ac6da4fea003c673aa07?convert_to_webp=true
6. Groups of carbon compounds
Life is based on carbon compounds including carbohydrates, lipids, proteins and nucleic acids.
Carbohydrates
• Composed of C, H and O
• General chemical formula (CH2O)x
• Used as fast-access energy storage molecules
• Glucose, fructose and galactose are
monosaccharides, that is, monomers used to
build more complex carbohydrates like starch or
glycogen (polysaccharides)
Macromolecules
• Molecules of large molecular
weight composed of simpler
organic compounds, known as
monomers, chemically bonded
among each other.
http://stopdiabetesmellitus.com/wp-
content/uploads/2015/01/Glucose.png
Glucose and other
monosaccharides are usually
found in ring structure
Fructose
http://www.wpclipart.com/science/atoms_mol
ecules/molecules/fructose.png
http://chemistry.gravitywaves.com/CHE452/images/Glycogen.gifGlycogen
http://img.medscapestatic.com/pi/meds/ckb/75/43975tn.jpg
7. Groups of carbon compounds
Life is based on carbon compounds including carbohydrates, lipids, proteins and nucleic acids.
Lipids
• Composed of C, H and O
• Include steroids, waxes fatty acids and
triglycerides
• Distinguished in fats (solids) and oils (liquid)
• Diverse group of molecules
https://upload.wikimedia.org/wikipedia/commons/b/be/Fat_triglyceride_shorthand_formula.PNG
Triglycerides
https://courses.washington.edu/conj/membrane/fattyacid.png
fatty acids
Saturated
Unsaturated
Polyunsaturated Saturated fatty acids contain no double bonds
in the carbon chain
Monounsaturated fatty acids contain one
double bond in the carbon chain
Polyunsaturated fatty acids contain many
double bonds in the carbon chain
Phospholipids
http://figures.boundless-cdn.com/18565/full/figure-05-01-03a.jpeg
Steroids
http://www.chem.latech.edu/~deddy/chem121/
Image195.gif
8. Groups of carbon compounds
Life is based on carbon compounds including carbohydrates, lipids, proteins and nucleic acids.
Proteins
• Composed of C, H, O, N (some may include sulphur)
• Proteins is a diverse group of macromolecules with
numerous functions within the cell.
• Proteins are macromolecules composed of simpler
monomers called amino acids.
Remember the numerous roles of the membrane proteins
http://www.nature.com/scitable/content/ne0000/ne0000/ne0000/ne0000/14706234/U3CP1-
4_MemProteinFunction_ksm.jpg
They also act as biocatalysts,
catalysing numerous
biochemical reactions.
http://4.bp.blogspot.com/-
T0SV3qOTFLI/UjToYXUpapI/AAAAAAAAACg/4EEjhi_pP-
g/s1600/catalase.gif
http://www.medicalnewstoday.com/content/images/articles/262/262881/collagen.jpg
Proteins may also have a structural role
Collagen
Antibodies are proteins participating in
specific immunity
https://www.amgenscience.com/static/files/amgenscience/img/episodes
/the-shape-of-drugs-to-come/monoclonal-antibodies/1.png
9. Groups of carbon compounds
Life is based on carbon compounds including carbohydrates, lipids, proteins and nucleic acids.
Nucleic acids
• Composed of C, H, O, N
• Nucleic acids are macromolecules
composed of monomers called nucleotides.
• Each nucleotide has three components: a
pentose sugar, a phosphate group and a
nitrogenous base.
• There are two main types of nucleic acids
DNA and RNA which differ on the type of
sugar and composition of nitrogenous
bases.
http://ib.bioninja.com.au/_Media/nucleotide_med.jpeg
A nucleotide
Nucleotides joined together via covalent
bonds form polynucleotide chains.
Two polynucleotide chains form the molecule
of DNA which is a double helix.
http://www.mhhe.com/biosci/ap/ap_prep/cem1s9_3.jpg
On the other hand, the RNA
molecule is single-stranded
http://www.wiley.com/legacy/college/boyer/0470003790/structur
e/tRNA/trna_diagram.gif
10. Ribose
Skill: Drawing molecular diagrams of glucose, ribose, a saturated fatty acid and a generalised
amino acid.
C
CC
C
C
O
Ribose is a pentose (has 5 carbons) forming a
ring of four carbons with a side chain (5th)
• Draw the ring of the molecule.
• Add the side chain.
• Number the atoms starting with number
one on the right.
• Add the –OH (hydroxyl) and H groups. Take
care of the order.
C
CC
C
C
O OH
H
H
OH
H
OH
H
H2OH
http://www.biotopics.co.uk/jsmol/ribose.html
11. Glucose
Skill: Drawing molecular diagrams of glucose, ribose, a saturated fatty acid and a generalised
amino acid.
Glucose is a hexose (has 6 carbons) forming a
ring of five carbons with a side chain (6th)
• Draw the ring of the molecule
• Add the side chain
• Number the atoms starting with number
one on the right.
• Add the –OH (hydroxyl) and H groups. Take
care of the order
C
CC
C
C O
C
1
23
4
5
6
H
OH
H
OH
OH
H
H
H2OH
C
CC
C
C O
C
1
23
4
5
6
OH
http://www.biotopics.co.uk/jsmol/alphabetaglucose.html
http://www.biotopics.co.uk/jsmol/alphabetaglucose.html alpha-D-glucose
12. Fatty acids
Skill: Drawing molecular diagrams of glucose, ribose, a saturated fatty acid and a generalised
amino acid.
Any fatty acid has a long unbranched carbon
chain with single bonds.
• Draw the carbon chain
• Add the carboxyl group (R-COOH).
Remember this is an extra carbon atom
• Add the H atoms
Butyric acid
C C C C
O
OH
Carboxyl group
C C C C
O
OH
Methyl group
H H H
H H H
H
http://www.raw-milk-facts.com/images/FatTrio.gif
http://www.biotopics.co.uk/jsmol/fattyacids.html#
Stearic acid
13. Amino acids
Skill: Drawing molecular diagrams of glucose, ribose, a saturated fatty acid and a generalised
amino acid.
amino group carboxyl group
The R is the functional group of each amino acid
and may correspond to different chemical groups
http://web.chem.ucla.edu/~harding/IGOC/A/amino_acid01.
png
carboxyl group
amino group
http://study.com/cimages/multimages/16/valine.png
Valine
https://upload.wikimedia.org/wikipedia/commons/6/62/Alanine.png
Alanine
14. Amino acids
Skill: Drawing molecular diagrams of glucose, ribose, a saturated fatty acid and a generalised
amino acid.
There are twenty one different amino acids participating in the structure of proteins with each one having a
different functional group.
Amino acids are grouped according to the properties of the functional groups.
http://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Amino_Acids.svg/2000px-
Amino_Acids.svg.png
15. Amino acids
Skill: Drawing molecular diagrams of glucose, ribose, a saturated fatty acid and a generalised
amino acid.
There are twenty one different amino acids participating in the structure of proteins with each one having a
different functional group.
Amino acids are grouped according to the properties of the functional groups.
http://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Amino_Acids.svg/2000px-
Amino_Acids.svg.png
16. Identifying molecules
Identification of biochemicals such as sugars, lipids or amino acids from molecular diagrams.
Identify the following molecules
Molecule 1
Molecule 2
Molecules 3
Molecule 4 Molecule 5
Molecule 6
17. Identifying molecules
Identification of biochemicals such as sugars, lipids or amino acids from molecular diagrams.
Identify the following molecules
Molecule 1
Molecule 2
Molecules 3
Molecule 4
Molecule 5 Molecule 6
Amino acid
Amino group
Carboxyl group
Polyunsaturated fatty acid
Long carbon chain with double bonds
Carboxyl group
Monosaccharide
C, H and O
Five carbons in a
ring and a side
chain
Monosaccharide
C, H and O
Five carbons in a
ring and a side
chain
Monounsaturated fatty acid
Long carbon chain with one double bond
Carboxyl group
Glycerol
(triglycerides)
18. The discovery of urea and the falsification of vitalism
Falsification of theories—the artificial synthesis of urea helped to falsify vitalism
In 1828 the German chemist Friedrich Wöhler synthesized urea
artificially using silver isocyanate and ammonium chloride
https://upload.wikimedia.org/wikipedia
/commons/thumb/3/32/Friedrich_Wöhl
er_Litho.jpg/800px-
Friedrich_Wöhler_Litho.jpg
http://www.evolution-
textbook.org/content/free/figures/04_EVOW_A
rt/05_EVOW_CH04.jpg
Till then, urea was known as a product of the kidneys and a
component of urine. Moreover, it was believed that living
organisms had a vital principle which among others, was giving
them the ability to produce organic compounds. This perception
was known as vitalism
Wöhler’s accidental discovery refuted the theory of vitalism and
proved that the synthesis or urea and other organic compounds
in living organisms is governed by the same basic principles of
chemistry and physics as in non-living matter.
Read more
https://www.sciencebasedmedicine.org/the-death-and-rebirth-of-
vitalism/
Please remember that there are still processes in living
organisms that have not been replicated in vitro. One of them is
the synthesis of the polypeptide chains in the ribosomes.
19. The natural and artificial synthesis of urea
Application: Urea as an example of a compound that is produced by living organisms
but can also be artificially synthesized.
Production in humans
• A series of enzymatically catalysed
reactions.
• Produced in the liver when there is
an excess of proteins / amino acids.
• Component of urine.
• Transported to the kidneys to be
filtered out and exit the body by
urine.
Artificial production
• Chemical reactions are not catalyzed
by enzymes.
• Over 100 million tones produced
annually.
• Used as a fertilizer.
• End product identical to naturally
produced.
https://s-media-cache-
ak0.pinimg.com/736x/fb/c9/f6/fbc9f62d6bdad037c9b4de249845d6f6.jpg
http://www.essentialchemicalindustry.org/images/stories/520_Urea/Urea_04.JPG
20. Metabolism
Metabolism is the web of all the enzyme-catalysed reactions in a cell or organism
Biochemical reactions happening within cells are catalyzed by globular proteins called enzymes
(revisited later in 2.5).
Most biochemical reactions are linked together in pathways where the products of one reaction
are the reactants of the next one. In this manner a molecule is gradually converted to another in
a series of small steps.
A + B ------> C + D ------> E
Enzyme 1 Enzyme 2
There is an immense number of
biochemical reactions which are
interconnected and form a dense
network (may look like a metro map)
which is commonly known under the
term metabolism
21. Anabolism vs Catabolism
Anabolism is the synthesis of complex molecules from simpler molecules including the formation of
macromolecules from monomers by condensation reactions.
Catabolism is the breakdown of complex molecules into simpler molecules including the hydrolysis of
macromolecules into monomers.
Anabolism
Purpose: The synthesis of macromolecules from
smaller ones.
Main type of reactions: Condensation reactions
Energetics: Energy consumption
Examples: Photosynthesis, protein and DNA
synthesis
Catabolism
Purpose: Break down of macromolecules
into simpler ones.
Main type of reactions: Hydrolysis
reactions
Energetics: Energy yield
Examples: Cellular respiration, digestion of
molecules in the intestine
Coupling of energy an matter
22. Condensation vs Hydrolysis
Anabolism is the synthesis of complex molecules from simpler molecules including the formation of
macromolecules from monomers by condensation reactions.
Catabolism is the breakdown of complex molecules into simpler molecules including the hydrolysis of
macromolecules into monomers.
The purpose of condensation reactions is to join monomers and bind them via covalent
bonds. A by-product of the process is water.
http://www.cengage.com/biology/discipline_content/animations/reaction_types.htm
l
Covalent bond
This is a condensation reaction
between two amino acids
https://upload.wikimedia.org/wikipedia/commons/thumb/6/6b/AminoacidCondensation.svg
/576px-AminoacidCondensation.svg.png
And this is a condensation reaction
between two monosaccharides
http://www.old-ib.bioninja.com.au/_Media/glycosidic-linkage_med.jpeg
23. Condensation vs Hydrolysis
Anabolism is the synthesis of complex molecules from simpler molecules including the formation of
macromolecules from monomers by condensation reactions.
Catabolism is the breakdown of complex molecules into simpler molecules including the hydrolysis of
macromolecules into monomers.
The purpose of the hydrolysis reactions is to break down polymers into simpler monomers
This is the hydrolysis reaction of a dipeptide into two amino acids
And this is a hydrolysis reaction of a disaccharide
into two monosaccharides
H2O
enzyme
https://figures.boundless-cdn.com/30381/large/hydrolysis%20reaction%20amino%20acids.png
http://figures.boundless-cdn.com/18550/full/figure-03-01-02.jpeg
http://www.cengage.com/biology/discipline_content/animations/reaction_types.htm
l
24. Condensation vs Hydrolysis
Anabolism is the synthesis of complex molecules from simpler molecules including the formation of
macromolecules from monomers by condensation reactions. Catabolism is the breakdown of complex
molecules into simpler molecules including the hydrolysis of macromolecules into monomers.