Honors Biology midterm

What is the difference between quantitative and qualitative data?

Quantitative: Numbers, Meters, Grams, Liter

Qualitative: Descriptive terms, Describing senses

What is science?

A body of knowledge, based on the study of the natural world

What is biology?

the study of life

What are the steps of the scientific method?

• Ask a question

• Make observations

• Form hypothesis

• Conduct experiment

• Analyze data

• Draw conclusion

What makes an experiment “controlled”?

an experiment in which all factors are held constant except for one: the independent variable

What is an independent variable?

The variable being changed

What is a dependent variable?

The data being collected

What are similarities between prokaryotic and eukaryotic cells?

Both have a plasma membrane, have genetic material in some form, ribosomes, cytoplasm and break down molecules to generate energy

What are the differences between prokaryotic and eukaryotic cells?

Prokaryotic cells have no membrane-bound organelles or nucleus, whereas eukaryotic cells do.

What is DNA?

deoxyribonucleic acid is the hereditary material in humans and almost all other organisms.

What is reproduction?

Creating offspring

What is homeostasis?

Keeps an organism’s internal condition stable

What is the order of levels of organization?

• Cells

• Tissues

• Organs

• Organ systems

• organisms

Describe the levels of organization above the organism level.

• Population

• Community

• Ecosystem

• Biome

• Biosphere

What subatomic particles make up an atom? What are their locations and charges?

Proton: Positive-Nucleus

Neutron: Neutral-Nucleus

Electron: Negative-Outer Ring

What are the rules for the number of electrons in the first 2 energy levels?

2 electrons in the first orbit, 8 electrons in the second orbit

What is an ion?  How do ions form?

Atoms with charges: are formed by the addition of electrons to, or the removal of electrons from, neutral atoms or molecules or other ions

What is the difference between an atom and a molecule?

Atoms are the fundamental unit of every matter that cannot be broken down further. It consists of electrons, protons, and neutrons. Whereas two or more similar or different kinds of atoms form a molecule

Define compound & give an example

a substance made from two or more different elements that have been chemically joined. Example: H2O and NaCl

How do you calculate the number of atoms in a molecule, when given its formula?

Atomic number=number of protons and electrons

Atomic Mass=number of protons+number of neutrons

How do ionic bonds form?

type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Example: NaCl

How do covalent bonds form?

when atoms share electrons on their outer shells to create a full set of electrons.

Why is water a polar molecule?

The oxygen part of water is negative, and the hydrogen parts of water are positive

How do hydrogen bonds form between water molecules?

between neighboring hydrogen and oxygen atoms of adjacent water molecules.

What is the difference between cohesion and adhesion?

Cohesion: Water likes to stick to itself

Adhesion: Water likes to stick to other things

What is an acid? What is a base?

Acid: more H+ ions

Base: more OH-

What is the relationship between H+ concentration and pH value?

As more H+ ions are added, the pH goes down

What does it mean for a molecule to be classified as “organic”?

molecules that are made of carbon and hydrogen, and can include other elements.

What is a reactant?  What is a product?

Reactants: The molecules that go into a reaction

Product: The molecules that are formed from a reaction

What is activation energy?

The minimum amount of energy needed for reactants to form products

How does an enzyme (catalyst) affect the activation energy of a chemical reaction?

A catalyst lowers the activation energy of a chemical reaction

How can you tell from a graph if energy is released or absorbed in a reaction?

If the graph goes down, then it is an exothermic reaction and energy is released. If the graph goes up, it is an endothermic reaction and the energy is absorbed.

What type of macromolecule is an enzyme?

A protein

How many bonds can carbon form?

four

What are the four macromolecules (polymers) that make up living things?

• Carbohydrates

• Proteins

• Lipids

• Nucleic acids

What are the monomers (building blocks) of: carbohydrates, lipids, proteins, and nucleic acids?

Carbohydrates: Monosaccharides (simple sugars)

Proteins: Amino acids

Lipids: Fatty acids and glycerol

Nucleic acids: Nucleotide

What are the main functions of: carbohydrates, lipids, proteins, and nucleic acids?

Carbohydrate: energy source

Lipids: energy storage (long term)

Proteins: structure, defense, transport, speeds up reactions

Nucleic acids: store and communicate genetic information

What are the three parts of cell theory?

• All living organisms are composed of one or more cells.

• A cell is the basic structural and functional unit of living organisms.

• All cells arise from pre-existing cells.

What features do all cells have in common?

• a cell membrane (also known as the plasma membrane)

• cytoplasm.

• ribosomes.

• DNA (genetic information)

Describe how prokaryotes and eukaryotes differ in: size, complexity, and location of DNA (nucleus or no nucleus)

Prokaryotic: Smaller, less complex, DNA stored in cytoplasm (no nucleus)

Eukaryotes: Bigger, more complex, DNA stored in nucleus

What organelles are unique to plant cells (not found in animal cells)?

cell wall, chloroplasts, plasmodesmata, and plastids used for storage, and a large central vacuole

What organelles are unique to animal cells (not found in plant cells)?

centrosomes (or a pair of centrioles), and lysosomes

Cell membrane:

regulates the transport of materials entering and exiting the cell.

Nucleus:

acts as the repository of genetic information and as the cell's control center.

Ribosomes:

is the site of protein synthesis in the cell.

Centriole:

made up of microtubules that function during cell division, they are located in the cells cytoplasm near the cells  nucleus.

Lysosome:

vesicles that contain substances that digest excess or worn-out organelles and food particles. Lysosomes also digest bacteria and viruses that have entered the cell.

Chloroplast:

Organelles that capture light energy and convert it into chemical energy through a process called photosynthesis.

Mitochondria:

converts fuel particles (mostly sugars) into energy for the cell to use.

Describe the polar and nonpolar regions of phospholipids.

The head (polar region) of each phospholipid molecule is oriented towards the exterior of the bilayer. The tail (nonpolar region) of each phospholipid molecule is oriented towards the interior of the bilayer.

What kinds of molecules can easily pass through a membrane?

Small nonpolar molecules Example: oxygen and carbon dioxide

What does “semi-permeable” mean?

Cells have control over what molecules can or cannot pass through

Define diffusion.

The net movement of particles from an area where there are many particles of the substance to an area where there are fewer particles of the substance

What are two differences between passive and active transport?

Passive: does not use energy, molecules move along the concentration gradient

Active: uses energy, molecules move against the concentration gradient

List 3 examples of passive transport.

• Diffusion

• Osmosis

• Facilitated diffusion

Define osmosis.

Diffusion of water across a membrane

Describe HYPOtonic solution and what happens to the cell as a result of being placed in a hypotonic solution.

Concentration of solute is lower outside the cell. Cell will burst if it is filled with too much water

Describe HYPERtonic solution and what happens to the cell as a result of being placed in a hypotonic solution.

Concentration of solute is higher outside the cell. Cell will shrivel up.

What is exocytosis?  What kinds of molecules exit the cell using exocytosis?

Exocytosis: secretion of materials out of the cell. Example: expelling wastes, or secreting a protein the cell made to reach another cell (like a hormone)

What is energy?

The ability to do work

What is the difference between catabolic and anabolic metabolism?

Catabolic: release energy by breaking down larger molecules

Anabolic: use energy to build larger molecules

How does ATP release energy?

ATP releases energy when the bond breaks between the 2nd and 3rd phosphate groups

What are the reactants and products of photosynthesis?

Reactants: Carbon dioxide and water

Products: Glucose and oxygen

What are the reactants and products of cellular respiration?

Reactants - glucose and oxygen

Products - Co2 and water

What is a pigment?

Pigments can capture sunlight. Chlorophyll is a pigment found in chloroplasts that make them green and contribute to photosynthesis.

Where do the light-dependent reactions take place?

In the thylakoid membrane

What are the reactants and products of the light-dependent reactions?

Sunlight and H2O are the reactants. ATP, NADPH, and O2 are the products.

Where do the light-independent reactions take place?

The stroma

What are the reactants and products of the light-independent reactions?

The reactants are CO2, NADPH, and ATP and the products are glucose, NADP+, and H2O.

What 2 pathways do plants in dry climates use for photosynthesis & list example plants.

Plants like cactus, pineapple, and aloe vera only open their stoma at night to conserve water. Water goes up through the roots and out through the leaves during gas exchange.

What are the 3 stages of cellular respiration?

Glycolysis, krebs cycle (citric acid cycle) and the electron transport system (oxydated phosphorylation).

What is the location, oxygen requirement (aerobic or anaerobic), and ATP production (number of) for each of the 3 stages of cellular respiration?

Glycolysis - cytoplasm (right outside of the mitochondria) anaerobic (no oxygen), 2 NET ATP are produced

Krebs Cycle (citric acid cycle) - In the matrix, aerobic (oxygen used), 2 NET ATP

Electron Transport system (oxidated phosphorylation) - in the inner membrane of the mitochondria aerobic (oxygen used), 32-34 ATP produced.

What are the reactants and products of glycolysis?

Glucose is the reactant; while ATP and NADH are the products

What is the total amount of ATP created during glycolysis?  What is the net amount of ATP created during glycolysis?  What does “net” gain mean?

4 ATP produced but only 2 NET ATP are produced. NET is the amount that is gained (profit)

What electron carriers are produced during the Krebs cycle?

Pyruvate is oxidized by the TCA cycle to provide reduced NADH and FADH2 as electron carriers

How many times does the Krebs cycle turn?

twice

What role does oxygen play in the electron transport chain?

Oxygen acts as a final electron acceptor that helps move electrons down a chain that results in ATP production

What role does ATP synthase play in chemiosmosis?

It adds a phosphate to ADP, making ATP

What is the total amount of ATP created during cellular respiration, per one glucose molecule?

36 - 38 ATP per glucose molecule

Which produces more ATP - fermentation or cellular respiration? (How many ATP?)

Cellular respiration is 16 times more efficient and produces 36

What types of organisms use alcohol fermentation?

yeasts and some other fungi and bacteria

Why do you feel muscle soreness during/after strenuous exercise?

Moving on glycolysis rather than all three steps, your body is telling you to slow down so it can generate more atp through cellular respiration rather than fermentation