Components of Living Things Notes
2/29/2008 10:03:00 AM
DO NOT PRINT THIS DOCUMENT. IT IS TOO LONG.
element: a substance that cannot be further broken down by a chemical
reaction (there are 92 naturally occurring elements)
compound: combination of elements in a fixed ratio (ex NaCl one sodicum
atom and one chlorine atom)
“C, O, H, N make up 96% of living matter” Campbell, 1996.
Carbohydrates
1) What is the role of a carbohydrate (sugar) in a cell?
Main use for energy/fuel and for building structures with in a cell or
organism (goes through glycolysis to harvest ATP to power the)
Role of carb at cellular level: to help build structures within the cell, to
produce energy by going through the path of glycolysis and producing ATP –
high energy molecules to fuel the cell so it can carry out all of its proceses
2) What is the role of a carbohydrate (sugar) in an organism (living thing)?
To provide energy/fuel for the organism, to provide nutrients for the
organism to live, some cells require only carbohydrates to do their jobs –
and can only use carbohydrates (sugars) for the energy to do their jobs
Role of carb at the organism level: to power the entire organism – give it
energy and matter to build different tissues and structures within the
organism’s body
3) What is the chemical make up of a carbohydrate? What elements are in
it?
Carbon, hydrogen, oxygen in fixed ratios
Ex:
Glucose is a hexose sugar (6 carbon sugar) C6H12O6
Ribose is a pentose sugar (5 carbon sugar) C5H10O5
4) What does the chemical structure of a carbohydrate look like? How are
the elements bonded together?
Glucose ball and stick model
http://staff.jccc.net/PDECELL/biochemistry/glucose.gif
Structural formula of glucose
http://www.palaeos.com/Fungi/FPieces/Images/Glucose.gif
Lactose: http://www.drugdeliverytech.com/cufm/jpg/002175.jpg
Where can you find carbohydrates?
Carbs come from:
http://www.faqs.org/nutrition/images/nwaz_01_img0048.jpg
and:
http://newsletter.wsu.edu/eplay/user_pics/375x250_veggies.j
pg
and from: http://www.fruitforyou.com.au/fruit-hampers-
melbourne/corporate-fruit-box.jpg
Carbohydrates are made of carbon, oxygen, and hydrogen in fixed ratios
Carbs are found in cell walls of plants, in the mitochondria going through the
process of glycolysis to harvest the energy from the carbohydrate, carbs are
located on the surface of cells and used in cell surface recognition,
5) How does a living organism obtain carbohydrates? Does an organism
need to eat carbs in order to obtain it?
An organism either eats a plant/fruit/starch/or other organism that has
ingested carbohydrates. If you are a plant, you make your own carbs
through the process of photosynthesis. If you are a human you need to eat
things that contain carbs.
6) Do any living things produce carbohydrates?
Yes, plants, and other photosynthetic algaes, plankton etc
7) What is glucose?
Simple sugar Carbohydrate – sugars – simple and complex
Glucose is a simple sugar ( monosaccharide – a single sugar)
8) What is starch?
Starch:
http://www.elmhurst.edu/~chm/vchembook/images/547starch.gif
starch granules:
http://www.public.iastate.edu/~pkeeling/startype.jpg
starch: storage polysaccharide found only in plants; starch is made of
glucose monomers strung together ; plants store starch in granules inside
organelles like plastids and chloroplasts
animals have enzymes that can break down starch into glucose monomers
and use the glucose for energy
9) What is cellulose?
cellulose: structural sugar in plants – used to make cell wall, cellulose is also
known as fiber, which humans cannot digest
10) What is chitin?
Chitin: polysaccharide made by arthropods (insects, spiders etc) to make
their exoskeleton – their hard crunchy case
chitin surgical thread: thread made of chitin used in surgery to stitch wounds
b/c the thread will eventually decompose and does not need to be removed
11) What is a mono, di, polysaccharide?
Mono- simple sugar (ex glucose)
Disaccharide – 2 monosaccharides linked together by a dehydration reaction
(condensation reaction) (lactose)
Polysaccharide – a bunch of monosaccharides linked together to form a
chain of sugars (starch), glycogen, cellulose, chitin
Proteins
What is the role of protein in a cell?
Proteins control almost everything in a cell and in an organism. Proteins are
responsible for moving things in a cell, for controlling the chemical reactions
within a cell, for controlling cellular processes (like glycolysis), for allowing
cells to be recognized by other cells, for copying DNA.
What is the role of protein in an organism?
To build tissues and organs, to control the movement of things throughout
the body, to control metabolic reactions, to control chemical processes, to
store energy for the body, they help w/ all biological processs, they are
catalysts, transport other molecules, store molecules, provide support for
the cell and organism, they provide defense (immune system), they help w/
movement, they help w/ nerve impulses, growth, they do almost everything
in a cell or an organism
What is the chemical makeup of a protein? What elements are proteins
made of? What does a protein look like? How is a protein bonded together?
What is the chemical structure of a protein?
Proteins made from the 20 amino acids. Amino acids are the monomers
(single unit, building block) of a polypeptide chain (polymer – multiple
monomers linked together). Proteins fold and created a 3D structure based
upon the amino acids in the chain, structure and function based on the
amino acid sequence and 3d Structure
Basic structure: central carbon w/ a hydrogen, carboxyl gp (COO or COOH),
amine gp NH3, and then a side chain ® that varies
ex:
http://www.hcc.mnscu.edu/programs/dept/chem/V.27/amino_acid
_structure_2.jpg
So an amino acid has nitrogen, carbon, hydrogen, oxygen, and then
elements that compose the side group – which are made of carbon,
hydrogen, oxygen, sulfur, nitrogen,
Bonded together by single covalent bonds, and some side groups have
double covalent bonds
Here are the 20 amino acids:
http://upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Am
ino_acids_2.png/600px-Amino_acids_2.png
A protein goes through 4 steps before becoming an actual protein. It starts
with linking the amino acids together into a polypeptide chain, and then the
chain folds in different ways, and ends up creating a 3D structure that has a
specific function.
http://cropandsoil.oregonstate.edu/classes/css430/lecture%2
09-07/figure-09-03.JPG
Hemoglobin is a protein in your body that is in red blood cells and transports
oxygen to the rest of your body. It has a specific 3D structure that fits its
function
http://www.nlm.nih.gov/medlineplus/ency/imagepages/19510.ht
m
Lactose intolerance: lactose is the sugar found in milk (yes there is sugar in
milk! Remember lactose is a disaccharide, which means it is made of two
simple sugar compounds chemically bound together). If you are lactose
intolerant then you have a deficiency in the enzyme (protein) lactase which
breaks down lactose for your body to process
Here is the computer generated image of lactase
http://160.114.99.91/astrojan/protein/pictures/lactase6.jpg
Where can you find protein in an organism?
Everywhere! In every cell, all over the body, doing a specific job.
How does a living organism obtain protein? Does a living organism make
protein?
Most microorganisms (like E. coli) can make all 20 amino acids through
various complex chemical reactions. Humans cannot make 9 of the 20
amino acids, and must get those 9 amino acids from consuming food. When
you consume protein (eating a steak) your body digests the protein and
breaks it down into amino acids. Then your body can use those amino acids
to make proteins to work in the cells in your body. Proteins that already
exist in your body are constantly broken down and the amino acids are
reused in the synthesis of new proteins. A protein is tagged with a specific
“label” (ubiquitin, a protein) if it needs to be broken down into its amino acid
components.
In order to make the amino acids, our bodies/cells have to obtain nitrogen
from a molecule of ammonia. The carbon in amino acids comes from
breaking down carbs and having carbs go through different biochemical
pathways
So some organisms make all their protein, some organisms need to eat
protein and break it down to synthesize the proteins their bodies need
What is an amino acid?
An amino acid is the monomer (most simple part) of a protein. Amino acids
are the building blocks of proteins. They are made of an ammonia group
linked to a carbon and other elements into a compound. An amino acid
bonds to another amino acid to form a dipeptide (or 2 amino acids linked
together). A polypeptide chain is a chain of amino acids linked together by
chemical bonds. There are 20 different amino acids. They have a basic
structure in common, but they differ from each other in one of their side
chains, which is made up of different elements in different combinations to
give the amino acid its specific characteristics.
An enzyme is a protein with a specific job. Enzymes are catalysts, which
means they are used to speed up the process of a chemical reaction in your
body. They are responsible for many of the metabolic chemical reactions in
your body. They help break down your food and get the energy out of your
food for your body to use.
How are proteins used in cellular transport? How are proteins used in
movement?
They are used to move molecules and compounds throughout the cell and
throughout an organism’s body. For example, hemoglobin is a protein. It
helps transport oxygen to all the parts of your body.
How are proteins used in defense (immune system)?
Some proteins (lysozymes) are enzymes that break down invasive bacteria
in your body,
Lipids
Lipids don’t like water, mostly nonpolar in structure, mostly made of
hydrogen and carbon linked together
3 families within the lipid category are: fats, phospholipids, steroids
What is glycerol?
Glycerol is a hydrocarbon with an OH group attached to it. It looks like this:
http://www.burns-petnutrition.co.uk/Images/TRIGLYCERIDE.gif
Glycerol links to a fatty acid. A fatty acid looks like this (see below) and
when 3 fatty acids link to a glycerol molecule (by forming covalent bonds) a
triglyceride is formed. A triglyceride (triacylglycerol) is what we know as a
“fat”.
http://www.oliveoilsource.com/images/triglyceride.jpg
Saturated – refers to that there are no double bonds in the hydrocarbon
chain of the fatty acid
Unsaturated: means there is one or more double bonds in the hydrocarbon
chain
http://pirate.shu.edu/~rawncarr/molmodel/fattyacids.jpg
Animal fats are saturated
http://www.dairy.com.au/consumers/images/dairyaustralia/agd
a_07_tatura_butter.jpg
Vegetable fats and fish fats are unsaturated (oils found at room emp that
are liquid like canola oil, olive oil, cod oil)
http://www.antoniocelentano.com/images/group%20small%20web.
jpg
Hydrogenated vegetable oil means that a fat that is normally unsaturated
has been chemically changed to be a saturated fat by adding more hydrogen
to the hydrocarbon tail of the fatty acid
What is the role of fat in a cell/organism?
Role of fat: to store energy, remember 1 g of fat has 9 cal of energy for
your body to use, to cushion organs, to insulate your body, to use as a
chemical messenger for reactions,
Where can you find lipids in an organism?
In every cell, tissue, in cell membranes, in fat cells that store the fat as
energy for use later, in fat tissue that cushions your organs, fat forms a
layer under your skin to insulate your entire body, steroids are used as
chemical messengers throughout your body,
What is a phospholipid?
Made of only 2 fatty acids attached to glycerol, and a phosphate group is
attached to glycerol too
The “head” of the phospholipids likes water b/c of its chemical structure, the
“tail” of the phospholipids do not like water because of their chemical
structure. Phospholipids are used to make cell membranes.
What is a steroid?
Steroids are lipids that are made of chemical ring structures. Cholesterol is
an example of a steroid. Steroids are used as chemical messengers that
transfer messages throughout the cells and body.
http://www.abc.net.au/health/library/img/cholesterol_struct
ure.gif
How does an organism obtain lipids?
They eat other things that have lipids (we eat fatty foods) but an organism
can also synthesize lipids, especially phospholipids and steroids.
Nucleic acids
What is a nucleic acid?
Nucleic acid is the general term for the compounds DNA and RNA
(deoxyribonucleic acid and ribonucleic acid).
What is heredity?
Heredity is passing a genome (the entire set of genes of an organism) from
one generation to the next generation. You inherited your genes from your
parents.
What is a gene?
Genes are made of DNA – they are a unit of inheritance. They are the
directions for making proteins and for making you.
What is a genome?
The entire set of an organism’s genes.
What is DNA?
Deoxyribonucleic acid (the instructions for life – the genetic material that
contains all the directions for programming everything in every cell, in an
entire organism.
http://www.biologycorner.com/resources/DNA-colored.gif
http://ocw.mit.edu/NR/rdonlyres/Biology/7-A12Fall2005/D4134A30-F348-4615-8B0A-D0CB5ED86081/0/chp_dna.jpg
What is the purpose of DNA?
DNA is the genetic material that you get from your parents and makes you,
you. It codes for synthesizing all the proteins and structures your cells and
your body needs to function. DNA controls the cell and its processes. It is
made of NUCLEOTIDES.
What are nucleotides?
The building blocks for DNA and RNA. There are 4 different nucleotides.
They have a pentose sugar (a sugar w/ 5 carbons) and the sugar is called
deoxyribose. It has a nitrogenous base (a structure made of nitrogen bound
to other elements) and it has a phosphate group (phosphorous and oxygen
bonded together). There are 4 different nitrogenous bases: cytosine (C),
thymine (T) adenine (A), and Guanine (G).
http://www.chemsoc.org/ExemplarChem/entries/2003/imperial_B
urgoine/nucleotide.jpg
http://www.viewingspace.com/genetics_culture/images_genetic
s_culture/gc_assign/nucleotide2.gif
http://www.nvo.com/jin/nssfolder/scrapbookcell/4%20nucleotide.jpg
What is RNA? What is the purpose of RNA
RNA is another type of nucleic acid. mRNA is used to transfer the message
from DNA to a machine that will translate the message into protein, that will
then have a job in your body. mRNA is a messenger (m = messenger).
Where are DNA and RNA found?
In the nucleus of a cell. The nucleus of a cell is like a control center – it
controls all the activities and processes of a cell. (A cell is the smallest unit
of life.)
Cycles
What is the nitrogen cycle?
http://www.biocrawler.com/encyclopedia/Nitrogen_cycle
Like every natural element, there is a fixed amount of nitrogen available on
our planet. We don’t “run out” of nitrogen because there is a very specific
cycle that it follows, and it is constantly being recycled through this system
known as the “nitrogen cycle”. Living organisms require nitrogen to
synthesize the molecular compounds in their bodies, especially nucleic acids
and proteins.
You do not need to memorize the cycle. You just need to understand that
nitrogen is constantly being used in different forms by different organisms.
http://www.cst.cmich.edu/centers/mwrc/nitrogen_cycle1.gif
What is the carbon cycle?
http://eo.ucar.edu/kids/green/cycles6.htm
http://www.kidsgeo.com/images/carbon-cycle.gif
Just like the nitrogen cycle, carbon is recycled too. We have a fixed amount
of carbon on earth, and so it is always cycling through this cycle.
Why is water important for living organisms?
Water is involved in many chemical reactions within an organism. It is
necessary for plant growth, it is necessary for all the organisms that live in
an aquatic or marine environment. It is necessary for you to have so your
body functions properly. Your cells need water. Water supplies fluid for
your blood, for many different things to work internally in an organism.
What is organic chemistry?
It is the study of compounds containing carbon and hydrogen. It was
thought that organic compounds were necessary for life, and they are, but
life requires other compounds as well. Many organic compounds, such as
nucleic acids, carbohydrates, lipids, and proteins are necessary for life.
Why are the following elements important for life: carbon, oxygen,
hydrogen, nitrogen, phosphorus, and sulfur?
Most of the compounds that exist – that make up the cells, tissues, organs,
systems in an organism consist of those elements. Carbon, hydrogen,
oxygen, and nitrogen make up 96% of all living matter (Campbell, 1996). P,
S, Ca, K, and a few other elements make up the remaining 4% of an
organism (Campbell, 1996).
2/29/2008 10:03:00 AM
2/29/2008 10:03:00 AM