Question and Answers on Chapter 5

What are two types of monosaccharides and how do they differ in structure?

Fructose and glucose are monosaccharides. They both have the same formula which is C6H1206 but the placement of the carbon atoms is different. Glucose is classified as aldehyde which is a carbonyl group with at least one hydrogen attached to it but fructose is classified as a ketone which is contains a carbonyl group with t

wo hydrocarbon groups attached to it.

Both carbohydrates and lipids are built of C,H,O. How can you tell them apart ?

They both have different amount of molecules and different ratios. Carbohydrate has C:O 1:1 ratio and lipids C:O ratio is really high in Carbon. The chemical structures are also different. For instance, fatty acids have long chain with a -COOH on one end and a -CH3 at the other. Carbohydrates general formula is CH2O. Carbohydrates have a ring shape but lipids don't.

Cellulose and starch are both made of repeating units of glucose. What is different about their structure that gives them such different chemical properties ?

They are both polysaccharides and used for storage and structure. They are both made of glucose. In starch, all the glucose molecules oriented in the same direction. But in cellulose, each glucose unit is rotated 180 degrees around the axis of the polymer backbone chain. Our body has enzymes to digest starch but not the cellulose. Cellulose is a lot stronger than starch.

Lipids don't have a common chemical structure. Why are they grouped together into the same macromolecule class?

They are called lipids because they share one important trait which is they are insoluble in water or in other polar solvents but are soluble in nonpolar substances like ether. It means that they are all hydrophobic.

Identify and describe the four levels of protein structure.

The primary structure is basically the order of amino acids. The secondary structure is the shape results from hydrogen bonding between the amino and carboxyl groups of adjacent amino acids. If the bonding produces a spiral, it is called alpha helix, if it looks like the pleats on a skirt it's then called beta pleated sheet. Tertiary structure is the third level of protein structure. Hydrogen bonding, ionic bonding, the hydrophobic bonds and the formation of disulfide bond contribute to the tertiary structure. Quaternary structure describes a protein that is assembled from two or more separated peptide chains.

How do saturated fats differ from unsaturated fats both in structure and in behavior?

The saturated fats have no double bonds while unsaturated fats have one or more C=C bonds. So unsaturated fats can accept more H. Saturated fats are found in animal products and processed foods. Saturated fats are not healthy since they can raise cholesterol. Unsaturated fats are found in nuts, avocados and oils. They are healthy and they can lower cholesterol.

Contrast and compare the structure of a fat, an oil and a phospholipid.

Phospholipids are similar to fats but they only have two fatty acids attached to glycerol. Instead of the third one, we now have Phosphate molecule. They make up cell membranes. They have both polar (hydrophilic) and nonpolar (hydrophobic) regions which is different than fatty acids. Fats usually contain saturated fatty acids and oils usually contain unsaturated fatty acids this is why fats are solid but oils are liquid.

The Structure and Function of Large Biological Molecules_Chapter 5

1. What are the four main molecules for life?

2. How does the synthesis and breakdown of polymers work?

3. What are the elemental compositions, general formulas, types and uses of Carbohydrates ?

For main molecules for life :

Carbohydrates, lipids, proteins and nucleic acids are the four main molecules which are

important for life. Carbohydrates, proteins and nucleic acids are huge so they are called macromolecules but they are also polymers which are composed by more than 2 monomers.

The synthesis and breakdown of polymers :

Monomers get together to create polymers. While this process since they are covalently bonding a water monomer gets lost. This is Dehydration Reaction. This process is facilitated by enzymes which are specialized macromolecules that speed up chemical reactions in cells.

Polymers break into monomers by Hydrolysis which is the opposite reaction of Dehydration so a water molecule comes. Hydrolysis breaks polymers by adding H20.

The structures and functions of Carbohydrates :

Carbohydrates are used for fuel, building materials and receptors. General formula of it is CH2O.There are 3 kinds of carbohydrates according to their number of sugar. Monosaccharides are the simplest carbohydrates since they just have 1 sugar molecule which is either glucose or fructose. They both have the sameformula which is C6H12C6 but their placements are different. Disaccharides are composed by 2 sugar molecules joined by a glycosidic linkage. It might be glucose + fructose, glucose+galactose or glucose+glucose. Polysaccharides are composed by more than 2 sugar molecules. They are basically polymers since they have tons of repeating units of a monosaccharide. Starch, glycogen, cellulose and chitin are polysaccharides.

5 main facts about this chapter :

. Proteins, carbohydrates and nucleic acids are hydrophilic but lipids are hydrophobic.

. A saturated fatty acid has a single covalent bond between each pair of carbon atoms, and each carbon has two hydrogen bonded to it.

. A phospholipid looks just like a lipid except that one of the fatty acid chains is replaced by a phosphate group (-PO3-2).

. There are four levels that describe the structure of a protein.

1. Primary structure

2. Secondary structure

3. Tertiary structure

4. Quaternary structure

. DNA is a polymer of nucleotides which are Adenine, Thymine, Cytosine, Guanine.

Video about structure of protein :

http://www.youtube.com/watch?v=lijQ3a8yUYQ

On this chapter, we learnt 4 main molecules that our body needs. Carbohydrates, proteins, nucleic acids and lipids. We learnt how polysaccharides are made by, what the structure of each of these molecules, and their importance for life. There are 5 different protein functions which are structural proteins, enzymes, storage proteins, transport proteins and defensive proteins.We also differ RNA from DNA by their different nucleotides which are Uracil and Thymine.

Carbon and the Molecular Diversity of Life_Chapter 4

1. Why carbon is important for life?

2. What are hydrocarbons and isomers?

3. What are the most important chemical groups?

Carbon is the backbone of life.

Living organisms are made up of chemicals which almost includes carbons. Carbon enters the biosphere by the action of photosynthesis and carbon can form molecules that are large, complex and diverse. Proteins, DNA are some of the molecules that have carbons. Carbons can make compounds with Hydrogen, Oxygen, Nitrogen, Sulfur and Phosphorus. Carbon compounds are called organic chemistry. Because organic molecules are those that have carbon atoms. Carbon is easy to form bonds since it has 6 electrons.

Hydrocarbons and Isomers

Hydrocarbons are organic molecules consisting of only carbon and hydrogen such as ethane (C2H6) , methane (CH4) and propane (C2H8). Hydrogens are attached to the carbon skeleton wherever electrons are available for covalent bounding. Isomers are compounds that have the same numbers of atoms of the same elements but different structures and so different properties. There are 3 different isomers; structural isomers which are dissimilar in the covalent arrangements of their atoms, geometrical isomers which have the same covalent partnerships but they

have different space arrangements and enantiomers which are isomers that are mirror images of each other.

7 important chemical groups.

Hydroxyl (OH)

Carbonyl (CO)

Carboxyl (COOH)

Amino (NH2)

Sulfhydryl (SH)

Phosphate (OPO3)

Methyl (CH3)

5 main facts from this chapter.

. The study of carbon compounds is called organic chemistry because of carbon's unique properties.

. Carbon has 6 electrons with 2 in the first electron shell and 4 in the second shell.

. Valence is the number covalent bonds that an atom can form. Nitrogen's valence is 3 but Carbon's is 4, Oxygen's is 2 but Hydrogen's is 1.

. Living matter is made mostly of carbon, oxygen, hydrogen and nitrogen with some sulfur and phosphorus.

. The chemical groups affect molecular function by being directly involved in chemical reactions, these chemical groups are known as functional groups.

Video :

http://www.youtube.com/watch?v=2C_6ax2TsV8

In this chapter, we learnt carbon and what kind of role it plays in the biological and chemical reactions.

Water and the Fitness of the Environment

1. Why is the water important for biology?

2. How does the polarity of water molecules work?

3. What are the emergent properties of water?

Water is essential for living.

All organisms are made of water and also their environments.3/4 of Earth is water and 70-95% of a cell is surrounded by water. Water can be found as solid, liquid and gas. All living organisms need water more than anything else.

The polarity of water molecules results in hydrogen bonding.

Water is composed by 2 hydrogen and 1 oxygen elements. Oxygen is more electronegative than hydrogen. It means the electrons of the covalent bonds spend more time closer to oxygen than to hydrogen. They are polar covalent bonds. The distribution is unequal.

The four emergent properties of water :

Cohesion

Moderation of Temperature

Insulation of Bodies of Water by Floating Ice

The Solvent of Life

In this picture, water behaves as if covered by an invisible film. Some animals can stand, walk or run on water without breaking the surface. This shows us the cohesion of water resulting from the collective strength of its hydrogen bonds.

5 main facts from this chapter :

. Water has a specific heat, heat is absorbed when hydrogen bonds break is released when hydrogen bonds form.

. Ice floats because it's less dense than liquid water . This allows life to exist under the frozen surfaces of lakes and polar seas.

. A water molecule can transfer an H plus to another water molecule to form H3O plus and OH minus.

. A substance that reduces the hydrogen ion concentration of a solution is called a base.

. The sphere of water molecules around each dissolved ion is called a hydration shell.

Video :

http://www.youtube.com/watch?v=QH1yphfgfFI

This third chapter is quiet harder than the first 2 chapters. It has more chemistry and chemical themes and made me get confused. In this chapter, we basically learned how the structure of a water molecule allows it to interact with other molecules.

The Chemical Context of Life_Chapter 2

1. How does an ant live?

2. How is the relationship of chemistry and biology?

3. How do the formation and function of molecules work?

Chemistry in ant's world.

Chemistry is really important in an ant's world. Since they don't see really well, they need chemical communication. Some type of ants use longlasting chemical cues

to identify themselves and to mark their area. This is why chemistry is really close to biological organisms and can be play a big role in life.

Chemistry connects to biology.

Biology is a multi-disciplinary science which is composed by biology itself, chemistry and physics. All organisms on Earth need essential elements such as oxygen ( O2) , carbon (C) and compounds such as water ( H2O ), corbondioxyde ( CO2) . So we can say that in order to live, communities need chemical substances. For instance ; Radioactive isotopes have many useful applications in biology. Scientists use measurements of radioactivity in fossils to date these relics of past life.

The formation and function of molecules depend on chemical bonding between atoms.

Chemical bonds form when atoms interact and complete their valence shells. Covalent bond is the sharing of a pair of valence electrons by two atoms. ( H2) If two atoms are unequal in their attraction for valence electrons, ( because of their opposite charges ) it makes an ionic bond.(NaCl) A hydrogen bond is an attraction between a hydrogen atom carrying a partial positive charge and an electronegative atom.

5 main facts from the reading :

. An element is a substance that cannot be broken down to other substances by chemical reactions.A compound is a substance consisting of two or more different elements combined in a fixed ratio.

. An atom is the smallest unit of matter that still retains the properties of an element. It has 3 kinds of particles which are neutrons, protons and electrons.

. The point at which the reactions offset one another exactly is called chemical equilibrium.

. A molecule's shape is determined by the positions of its atom's valence orbitals.

. Chemical reactions change reactants into products while conserving matter and all chemical reactions are theoretically reversible.

Video about chemical bonding :

http://www.youtube.com/watch?v=ERy18NwemVc

In this chapter, we learned the basic chemistry like atoms, bonds, elements, isotopes. We learn how the biology science need chemistry to improve and to find out new style of lives like ants living near by Duroia Trees in Peru.There are 3 different kinds of bonds such as covalent bonds, ionic bonds and hydrogen bonds. In the nature there are so many chemical reactions of the various types of molecules which are important to life.

Themes in the Study of Life_Chapter 1

1. What are the levels of biological organizations?

2. What kinds of forms do scientists use in their study if nature?

3. What is the core theme of biology?

Levels of Biological Organizations

The Biosphere > Ecosystem > Communities > Populations > Organs and Organ Systems > Tissues > Cells > Organelles > Molecules

Scientists use two main forms of inquiry in their study of nature.

There is no single scientific method that scientists must follow. However there is the main types of scientific inquiry :

Discovery Science

Hypothesis-Based Science

Discovery science is like descriptive science. It's used by observation and analysis of data. Microscopes, photographs, movies are used in discovery science. Data is recorded observation. The type of logic in discovery science is Inductive Reasoning. It's to generalize from a large of

specific observations.

Hypothesis-Based science propose and test hypothetical explanations. Hypothesis is a tentative answer to a well-fra

med question, educated guess, based on experience and the data available from discovery science. The type of logic is now deductive reasoning. Find a specific result from a general premise. This specific result is found by predictions of experimental or observational results.

The core theme of biology is Evolution.

Evolution is biology's core theme. The scientific explanation for unity and diversity on Earth and for the suitability of organisms to their environments is evolution. '' Nothing in biology makes sense except in the light of evolution " by Theodosius Dobzhansky. Scientists group species according to their similarities, domains and kingdoms. ( Taxonomy ) Charles Darwin proposed natural selection as the mechanism for evolutionary adaptation of populations to their environments.

5 main facts from the chapter :

. The biosphere consists of all the environments on Earth that are inhabited by life.

. Ecosystem has two process . Cycling of nutrients and production of energy from sunlight.

. In life's structural hierarchy, the cell has a special place as the lowest level of organization that can perform all activities required for life.

. Genetic information is encoded in the nucleotide sequences of DNA.

. A scientific theory is broad in scope, generates new hypotheses and is supported by a large body of evidence.

This chapter is the first chapter of the book 'Biology' by Campbell and Reece and 5 other authors. This is the introduction of the book and of the biology itself. We learn the basic steps of biology such as its themes, how scientists discover the world and how the biology itself runs on Earth. We learn the relationship of science, technology and society, the culture of science, Charles Darwin and his theories.