biology midterm Flashcards

1
Q

What is biology?

A

The study of life

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2
Q

What are the components.of a science experiment and the order they occur?

A
  • Observing, state the problem,
  • created hypothesis,
  • starting experiment to test hypothesis,
  • analyzing data,
  • evaluating data.
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3
Q

What are the basic units of mass, length and volume in the metric system?

A
  • mass-grams,
  • length-centimeters,
  • volume-liters
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4
Q

What is the metric system?

A

The metric system is an international decimalised system of measurement.

Originally based on the mètre des archives and the kilogramme des archives introduced by France in 1799.

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5
Q

List and describe the 8 characteristics of life

A
  • cells-basic unit of life
  • need for energy-all organisms need energy for their life processes
  • metabolism-chemical processes that build or break their materials
  • adaptation-inherited trait that gives an advantage to an individual organism
  • homeostasis-maintenance of constant internal conditions in an organism
  • reproduction and development-organisms must have the ability to reproduce and grow
  • evolve-change things over time
  • pass on heredity-DNA
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6
Q

Define Homeostasis

A

Maintenance of constant internal conditions in an organism

(1) The tendency of an organism or a cell to regulate its internal conditions, usually by a system of feedback controls, so as to stabilize health and functioning, regardless of the outside changing conditions
(2) The ability of the body or a cell to seek and maintain a condition of equilibrium or stability within its internal environment when dealing with external changes

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7
Q

Describe the structure of an atom

A
  • In the center of an atom there is a nucleus which is a cluster of protons and neutrons.
  • The protons have a positive electric charge while the neutrons are neutral.
  • Orbiting the nucleus are electrons.
  • Electrons are negatively charged particles.
  • If the electrons and protons are not equal then the atom is an ion.
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8
Q

list and describe the subatomic particles.

A

The subatomic particles are protons, neutrons, and electrons.

  • Protons have a charge of +1, and they are in the nucleus of an atom.
  • Neutrons have no charge and they are also found in the nucleus of an atom.
  • Electrons have a charge of -1 they are found in specific orbits around the nucleus and are held in orbit by the positive charge of the protons in the nucleus.
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9
Q

What is a molecule?

A

A group of atoms bound together, representing the smallest fundamental unit of chemical compound that can take part in a chemical reaction.

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10
Q

What are the properties of water (cohesion, polar, high specific heat)?

A

Water’s boiling point is 212°F water has cohesion which means it can stick to itself very easily.

Water is colder so we can dissolve many other polar molecules (Solvent).

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11
Q

What causes water to have high specific heat?

A

Hydrogen bonding between water molecules. The hydrogen bonds are the strongest therefore take a lot of high specific heat capacity.

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12
Q

What is an ion? How are they formed?

A

An ion is an atom with a net charge due to the loss or gain of one or more electrons

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13
Q

Describe hydrogen bonds.

A

A hydrogen bond is a special type of dipole that exists between an electronegative atom.

This type of force always involve a hydrogen atom and the energy of this attraction is close to that of weak covalent bonds.

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14
Q

What is an enzyme?

A

A substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction.

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15
Q

Define substrate and active site.

A

Substrate is the reactant in which an enzyme reacts out.

Active Site is a special region of the enzyme where the substrate binds forming a temporary enzyme-substrate complex.

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16
Q

differentiate between competitive inhibitors and noncompetitive inhibitors.

A

Competitive inhibitors:
binds to the active site so the substrate cannot.

Noncompetitive:
binds somewhere else but change the shape

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17
Q

list the steps of enzyme catalysis in order.

A
  • The substrate enters the active site.
  • The substrate and enzyme change shape.
  • The product is expelled.
  • The enzyme reverts to its original configuration.
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18
Q

what factors affect whether or not an enzyme can function?

A

Dehydration:
dryness due to the removal of water.

Hydrolysis:
the chemical breakdown of a compound due to reaction with water

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19
Q

define activation energy.

A

The energy that an atomic system must acquire before a process.

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20
Q

Differentiate between exothermic and endothermic reactions

A

Exothermic reactions are reactions give off energy. Endothermic reactions absorbed energy.

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21
Q

what is a chemical reaction?

A

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.[1] Classically, chemical reactions encompass changes that strictly involve the motion of electrons in the forming and breaking of chemical bonds between atoms, and can often be described by a chemical equation.

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22
Q

What happens during a chemical reaction (ie how are substances changed)?

A

Process by which substances change into different substances through the breaking and forming of chemical bonds. Their atoms are rearranged.

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23
Q

Differentiate between reactants and products in a chemical reaction

A
  • The reactants are the parts that react in

* the products are what you get as a result of the reaction.

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24
Q

what are the 4 groups of organic compounds?

Describe each.

A

Protein:
polymer composed of amino acids linked by peptide bonds.

Fat:
a mixture of lipids

Nucleic acid:
various macromoles composed of nucleotide chains that are vital constituents of all living cells.

Carbohydrate:
simple sugars with small molecules as well as macromolecular substances.

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25
Q

which organic compounds do we get from food?

A
  • Carbohydrates
  • protein
  • starch
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26
Q

What is the difference between prokaryotes and eukaryotes?

A
  • prokaryotic cells do not have a nucleus and eukaryotic cells do.
  • prokaryotic cells lack some organelles and eukaryotic cells do not.
  • prokaryotic cells are not found in humans and eukaryotic cells are.
  • prokaryotic cells are always unicellular and eukaryotic cells are often multicellular.
  • prokaryotic cells reproduce/divide by binary fission and eukaryotic cells reproduce/divide by mitosis/meiosis
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27
Q

What are the organelles in a cell? What are their functions?

A
  • cytoskeleton a network of proteins that is constantly changing to meet the need of the cell
  • the nucleus is the storehouse for most of genetic information or DNA in cells
  • to endoplasmic reticulum is an interconnected network of thin folded membranes numerous processes including the production of proteins and lipid occur both on the surface of the ER and inside the lumen
  • ribosomes tiny organelles that linked amino acids together to form proteins ribosomes are about the site of protein synthesis and active participant in the process
  • Golgi apparatus consists of closely layered stacks of membranes enclosed spaces that process sort and deliver proteins.
  • Vesicles used to describe small membrane-bound sacs that divide some material from the rest of the cytoplasm and transported these materials from place to place within the cell
  • mitochondria supply energy to the cell
  • vacuole is a fluid filled sac used for the storage of materials needed by cell these materials may include water food molecules inorganic ions and enzymes most animal cells contain many small vacuoles plan are unique and have a large will vacuole
  • lysosome membrane bound organelles that contain enzymes they defend itself from invading bacteria and viruses they also break down damaged or worn out cell parts lysosomes tend to be numerous in animal cells
  • centrioles are cylinder shaped organelles made this short microtubule us arrange in a circle
  • cell wall which is a rigid layer that gives protection support and shape to a self the cell walls of multiple cells can add here to each other to health for the entire organism in plants and algae is made cellulose
  • chloroplast are organelles that carry out photosynthesis a series of complex chemical reactions that convert solar energy into energy rich molecules that the cell can use
28
Q

How do plant and animal cells differ?

A
  • Plant cells have cell walls
  • Plant cells have chlorophyll, the light-absorbing pigment required for photosynthesis.Similarly, chlorophyll containing plant cells go through both photosynthesis and cellular respiration, while animal cells only go through cellular respiration.
  • Plants cells have a large, central vacuole. While animal cells may have one or more small vacuoles, they do not take up the volume that the central vacuole does (up to 90% of the entire cell volume!).
  • Animal cells have centrioles, cilia (unicelluar animal cell), and lysosomes. Plant cells have no need for centrioles because their spindle fibers connect to the cell wall.
29
Q

Why is it important for cells to remain small?

A

Cells need to be small in order to have good surface area to volume ratios. It is important that the surface area be larger than the volume so that the things that need to get in and out of the cell can do so. Otherwise the cell could be poisoned by accumulation of waste or not being able to take in what it needs.

30
Q

Define homeostasis.

A

Maintenance of constant internal conditions in an organism

31
Q

What is the difference between diffusion and osmosis?

A

Diffusion is the movement of molecule from a place of high concentration to a place of low concentration through a semi-permeable membrane.

Osmosis is the movement of molecules from a place of high water concentration to a place of low water concentration through a semi-permeable membrane.

32
Q

Explain how molecules move in diffusion/osmosis.

A

they move across a semi permeable membrane

33
Q

Define active transport, how is it different from passive transport?

A

The movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy. passive transport requires no energy

34
Q

Define facilitated diffusion.

A

Facilitated diffusion is a process of passive transport with this passive transport aided by integral membrane proteins.

35
Q

Pinocytosis

A

The ingestion of liquid into a cell by the budding of small vesicles from the cell membrane.

36
Q

Exocytosis

A

A process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane

37
Q

Phagocytosis

A

The ingestion of bacteria or other material by phagocytes and ameboid protozoans.

38
Q

Receptor Mediated Endocytosis

A

Receptor-mediated endocytosis (RME), also called clathrin-dependent endocytosis, is a process by which cells internalize molecules (endocytosis) by the inward budding of plasma membrane vesicles containing proteins with receptor sites specific to the molecules being internalized.

39
Q

hypotonic

A

contains a low concentration of solute a high concentration of solvent (water).

40
Q

hypertonic

A

contains a high concentration of solute a low concentration of solvent (water).

41
Q

isotonic

A

contains the same concentration of solute the same concentration of water, as a cell.

42
Q

Describe the structure and function of the cell membrane.

A

forms a boundary between a sale and the outside environment and control the passage of materials into and out of the cell. The cell membrane consists of a double layer of phospholipids interspersed with a variety of other molecules

43
Q

What is ATP? How is energy released from ATP?

A

adenosine triphosphate

A molecule that transfers energy from the breakdown of food molecules to cell processes.After a simple reaction breaking down ATP to ADP, the energy released from the breaking of a molecular bond is the energy we use to keep ourselves alive.
When the phosphate group is removed.

44
Q

What is photosynthesis (what is the energy conversion that takes place)?

A

the process by which plants and some other organisms use sunlight to synthesis foods from carbon dioxide and water.

45
Q

What are the reactants and products of photosynthesis?

A

water and carbon dioxide are the reactants and the product is glucose and oxygen.

46
Q

What is the equation for photosynthesis?

A

6CO2+6H2O—–> C6H12O6 +6CO2

47
Q

Explain what happens in the Calvin Cycle and the Light-Dependent Reactions.

A

During the Calvin cycle, plants use energy that NADPH and ATP contain to build high-energy compounds that can stored up to a long period of time.

48
Q

Where does photosynthesis occur?

A

photosynthesis occurs in the chloroplast.

49
Q

Where does the Calvin Cycle take place?

A

the calvin cycle takes place in the stroma.

50
Q

Where do the light-dependent reactions take place?

A

the light dependent reactions take place in the chlorophyll

51
Q

What is cellular respiration?

A

the metabolic processes whereby certain organisms obtain energy from organic molecules

52
Q

What are the reactants and products of cellular respiration?

A

The reactants are the materials needed for the process: glucose and oxygen.

53
Q

What is the equation for cellular respiration?

A

C6H12O6+6O2——> 6CO2+6H2O+36ATP

54
Q

Where does cellular respiration take place?

A

the mitochodrion

55
Q

What are the 3 stages of cellular respiration?

A

1) Glycolysis: the cytoplasm
2) Krebs Cycle/The Citric Acid Cycle: mitochondria
3) Electron Transport Chain: the mitochondria (specifically, the inner mitochondrial membrane)

56
Q

Define fermentation. When does it occur? How much ATP is made?

A

The chemical breakdown of a substance by bacteria, yeasts, or other microorganisms,

typically involving effervescence

and the giving off of heat

57
Q

What is mitosis?

A

A type of cell division that results in two daughter cells each the same as the parent nucleus

58
Q

What are the 4 phases of mitosis and what happens during each?

A

Prophase-
chromatin condenses into chromosomes which are in pairs, centrioles start to split apart and move towards separate poles and the nuclear envelope dissolves. Spindle fibers begin forming.

Metaphase-
the chromosome pairs line up at the center or “equator” of the cell and spindle fibers attach. This pulls the chromosomes, now split apart called the sister chromatids. It can be remembered by this Metaphase Middle.

Anaphase-
Spindle fibers pull the sister chromatids apart. The sister chromatids start to move towards the poles and move towards the poles.

Telophase-
the sister chromatids reach the poles. A nuclear envelope forms around them. Two cells form. Then cytokinesis occurs.
Cytokinesis is the actual pinching off of the cytoplasm and the cell membrane. Cytokinesis happens during telophase but is a different process.

59
Q

What happens during interphase?

A

The cell copies its DNA and growth in preparation for division. The DNA is loosely organized during interphase.

60
Q

What are the 3 phases of interphase and what happens during each?

A

Gap 1 (G1) cells grow carry out normal functions and replicate your organelles. Synthesis (S) DNA synthesis. Gap 2 (G2) additional growth

61
Q

What regulates the cell cycle?

A

The Cyclin

62
Q

What is cancer?

A

uncontrolled cell growth

63
Q

What is meiosis?

A

A type of cell division that results in two daughter cells each with half the chromosome number of the parent cell.

64
Q

How are meiosis and mitosis different?

A

mitosis occurs in body cells meiosis occurs in sex cells. in mitosis each new cell has the same number of chromosomes as the parent in meiosis each daughter cell has half the number of chromosomes as the parent

65
Q

Explain the difference between haploid and diploid. Give examples of cells for each

A

A haploid cell has only one set of chromosomes. A diploid cell has two sets of chromosomes. In human, the somatic cells are diploid, and the gametes are haploid.

66
Q

Explain the difference between asexual and sexual reproduction

A

asexual reproduction has only one parent

sexual reproduction has two.


67
Q

What is crossing over?

A

The exchange of genetic material between homologous chromosomes that occurs during meiosis and contributes to genetic variability.