Final Test

What are the 7 properties of life?

Order, Reproduction, Growth & Development, Energy Utilization, Homeostasis, Evolutionary Adaptation and Response to the Environment.

What are the 10 levels of organization?

Atoms, Molecules, Organelles, Cells, Tissues, Organs, Organisms, Populations, Communities, Ecosystems ( A MOC Took Out Orange Pekoe Clothes. Excellent!).

What are the main differences between populations, communities and ecosystems?

Population - one type of species in a specific areaCommunities - sum of all species in a specific areaEcosystems - sum of all species and their abiotic environment in a specific area

Define homeostasis

Regulation of the internal environment, the tendency toward a stable equilibrium.

Define photosynthesis

Transformation of solar energy into chemical energy.

In which organisms does photosynthesis occur?

Plants, algea and some bacteria.

What organelle in plants and algea perform photosynthesis?

The chloroplast.

What compound found in certain bacteria perform photosynthesis?

The chlorophyll.

What is the chemical formula for photosynthesis? (include energy)

6CO2 + 6H2O + solar energy -\> C6H12O6 + 6O2

In which organisms does cellular respiration occur?

In all organisms.

What organelle found in all organisms (excluding bacteria) perform cellular respiration?

The mitochondria.

What does cellular respiration release?

Chemical energy in the form of ATP.

What is the chemical formula for cellular respiration? (include ATP)

C6H12O6 + 6O2-\> 6CO2 + 6H2O + ATP.

What is the full name of ATP?

Adenosine triphosphate.

What are the ATP's 3 main functions? Give an example for each function.

1. Cellular work - e.g. muscular contraction, chromosomal movements during cell division, etc.
2. Transportation - e.g. pumping molecules accross membranes, etc.
3. Chemical reactions - e.g. making proteins, etc.

What is an ATP composed of?

A nitrogen base called adenine

A 5-carbon sugar called ribose

3 negatively charged phosphate groups

What chemical reaction occurs when water is involved in breaking the bonds?

Hydrolysis.

What is the chemical formula for the decomposition of ATP (include energy)

ATP + H2O -\> ADP + ℗ᵢ + energy

What does ℗ᵢ symbolize?

Inorganic phosphate.

True or false? ATP is an renewable resource.

True.

What is the main difference beween catabolic and anabolic reactions?

Catabolic (exergonic) reactions: releases energy by decomposing molecules

Anabolic (endergonic) reactions: absorbs energy to construct molecules

What are the 2 types of classifications of organisms based on how they obtain their energy? Give an example for each.

Autotrophs - e.g. plants, some bacteria and algea

Heterotrophs - e.g. animals

What is the main characteristic of autotrophs?

They make their own organic molecules/food via photosynthesis.

What is the main characteristic of heterotrophs?

They need to consume other organisms to survive. They cannot make their own food.

What are the two main ways elements in an ecosystem interact with eachother?

Energy flow and chemical recycling.

Name an example of an abiotic factor in an ecosystem.

e.g. temperature, water, sunlight, wind, rocks, soil, etc.

How are species grouped in a food chain?

They are grouped into trophic levels.

What are trophic levels based on?

Feeding relationships and routes of energy flow through recycling.

What is a food chain?

A pathway for food transformation from trophic level to trophic level.

What does A → B mean in a food chain?

B is eating A; B is getting its energy from A.

What must all food chains contain?

An autotroph at the bottom.

What are the different trophic levels called? Explain briefly.

Primary producers - photosynthetic autotrophs

Primary consumers - heterotroph herbivores

Secondary consumers - herbivore-eating carnivores

Tertiary consumers - carnivore-eating carnivores

Decomposers - decomposers

What species are part of the decomposers?

Prokaryotes and fungi.

What do decomposers eat?

Dead organisms and waste (detritus).

True or false? Trophic levels higher than 3 are not possible. Explain briefly.

False. However, they are quite rare, as the amount of energy is so drastically reduced.

What important role do detritivores/decomposers play in the food chain?

They connect all trophic levels.

What is the definition of biomass?

Total dry weight of a trophic level

Complete the blank with + or - :

Left : +, +, - Right: -, -, +

Which percentage of energy is effectively transferred to the next trophic level? What happens to the rest?

10%. The rest is lost to the environment.

What is secondary production?

Amount of chemical energy in food converted to new biomass during a given period of time.

What is this diagram called?

An energy pyramid

What is this type of diagram called?

A pyramid of biomass

Which trophic level are most vunerable to toxic compounds? Why?

The top level because their biological accumulation is higher.

What is the most important difference between energy and chemical nutrients in an ecosystem?

Energy enters and exits an ecosytem. Chemical nutrients cycle within.

How does energy flows into and out of an ecosystem?

It enters in the form of solar energy and leaves through the heat released by organisms.

Choose the answer: water is a polar/non-polar molecule.

Water is a polar molecule.

What is the main characteristic of a polar molecule?

It has an unequal charge distribution.

Why are water molecules polar?

Since oxygen is more electronegative than hydrogen, a water molecule's electrons spend more time around the oxygen atom than around the hydrogen atoms.

What are hydrogen bonds (H-bonds)?

When a hydrogen forms a bond with another molecule's oxygen.

How many H-bonds can a molecule of water have?

4 H-bonds.

When does covalent bonding occur?

When 2 atoms share electrons.

What determines whether or not a molecule is polar?

If 2 atoms have around the same electronegativity, their bond will be non-polar. If not, their bond is polar.

What are the 4 consequences of water's polarity?

Cohesion, adhesion, high specific heat and high heat of vaporization.

Why is water cohesive?

H-bonds cause water molecules to stick to each other.

Why can some insects walk on water?

Cohesion causes water to have a high surface tension: the surface is resistant to breakage.

What is adhesion in water?

Water can H-bond to walls in vessels to counteract gravity.

What allows upward transport of water in plants?

Cohesion and adhesion.

What is the main difference between cohesion and adhesion?

Cohesion: water is attracted to water

Adhesion: water is attracted to other substances

What does having a high specific heat mean?

It is more resistant to changes in temperature.

Why does water have a high specific heat?

To heat up water, some energy must be used to break the H-bonds for water molecules to move faster.

How does water's high specific energy benefit life on Earth?

\-Stabilizes the temperature of the air nearby

\-Moderates the temperature of the Earth

\-Allows bodies of water to heat up slowly

What does having a high heat of vaporization mean?

A lot of heat must be absorbed for a substance to evaporate.

How does water having a high heat of vaporization help animals?

It helps moderate the temperature of animals. When animals sweat, water evaporates and leaves the skin cooler.

Why is ice less dense than liquid water?

In liquid water, H-bonds are constantly forming and breaking. This allows molecules to get closer together. In ice, H-bonds no longer break. The water molecules are therefore locked at a fixed distance between each other.

What are the consequences of ice being less dense than liquid water?

Ice floats on liquid water. This prevents deep bodies of water from freezing solid, protecting aquatic life.

What substances dissolve in water? What is this type of substance called?

Ionic compounds and polar covalent compounds dissolve in water. They are called hydrophilic substances.

What substances don't dissolve in water? What is this type of substance called?

Non polar covalent compounds don't dissolve in water. They are called hydrophobic substances.

What is the main difference between dehydration(condensation) and hydrolysis?

Dehydration is the synthesis of a polymer from multiple monomers. Molecules of water are released.

Hydrolysis is the decomposition of a polymer to multiple monomers. Molecules of water are absorbed.

What is the definition of a polymer?

A polymer is a substance consisting mainly of the same type of monomers bonded together.

What are the 4 types of macromolecules?

Carbohydrates

Lipids

Proteins

Nucleic acids

What do carbohydrates consist of?

Simple sugars and their polymers.

What are the goals of carbohydrates?

To serve as fuel for cells and as carbon sources to build other molecules.

What is a monosaccharide?

Sugar monomer, simple sugar.

What is the general formula of a monosaccharide?

(CH2O)n

How do monosaccharides serve as a major source of nutrients for cells?

They store energy in their chemical bonds, which can be broken by cellular respiration to produce ATP.

True of false? ATP can be stored if energy is not immediately required.

True.

Which word is used to designate 5-carbon sugars?

Pentose.

Which word is used to designate 6-carbon sugars?

Hexose.

What are the types of 5-carbon sugars?

Ribose and ribulose.

What are the types of 6-carbon sugars?

Glucose, galactose and fructose.

What are the types of disaccharides? How are they formed?

Glucose + glucose → maltose

Glucose + fructose → sucrose

Glucose + galactose → lactose

What geometric shape does glucose form when it enters the body?

A ring.

What is the main difference between alpha glucose and beta glucose?

In alpha glucose, the OH group on C1 is below the ring.

In beta glucose, the OH group on C1 is above the ring.

What is the name of the linkage between two monosaccharides?

A glycosidic linkage.

Replace each number by its respective polysaccharide

1. Starch
2. 2. Glycogen
3. 3. Cellulose
4. 4. Chitin

Polysaccharides formed by alpha glucose serve which purpose?

They serve as energy storage (energy polymers).

Polysaccharides formed by beta glucose serve which purpose?

They serve structural support (strucutre polymers).

What is the main structural difference between starch and glycogen?

Starch is unbranched while glycogen is branched.

What is the main structural difference between cellulose and chitin?

The C2 of the beta glucose has a OH in cellulose and a NH in chitin.

Why can cows eat grass \>:(((((((

They have a special enzyme in their digestive system that digest glycosidic linkages.

Among the 4 types of macromolecules, which is not a polymer?

Lipids.

True or false: lipids are soluble in water

False, they are hydrophobic.

What are the 3 kinds of lipids?

Fats, phospholipids and steroids.

What do fats consist of?

A glycerol (a 3-C alcohol) and 3 fatty acids.

What is the general formula for fatty acids?

CH3(CO2)nCOOH

Why are fats hydrophobic?

They are hydrophobic due to their hydrocarbon chain.

What is the name of the linkage between a fatty acid and a glycerol?

An ester linkage.

What are the main functions of fats?

1. Storage of energy
2. 2. Protection of internal organs
3. 3. Heat loss prevention

True or false: polysaccharides contain twice as much energy per gram as fats

False, fats contain twice as much energy per gram as polysaccharides.

What is this type of fat?

Saturated fat