Goal 2 Review

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Transcript Goal 2 Review

Biochemistry Unit Review
Part 1
Biomolecules
“Organic” molecules have carbon.
“Inorganic” molecules do not have carbon.
Monomers are small parts that make up a large
polymers.
Monomer + Monomer + Monomer = Polymer
Biomolecules
Organic
Molecule
Carbohydrate
Elements
C, H, O
Lipid
C, H, O
Protein
C, H, O, N
Function
Fast energy
Monomer
Test
Benedict’s –
Monosaccharide glucose
s (like glucose) Iodine starch
Store longterm energy, Fatty acids and
make up cell glycerol
membranes
Growth and
repair, speed
Amino acids
up chemical
reactions
Paper bag
Biuret’s
DNA: carries
Nucleic
Acid
C, H, O, N, P
hereditary
info
Nucleotides
RNA: makes
proteins
Is it living?
Water & pH
Water is a universal solvent – it dissolves most molecules and
ions.
pH is a measure of the amount of Hydrogen ions in a solution.
pH scale goes from 0 – 14.
1-6 = Acid – the lower the pH, the stronger the acid.
Ex. 2 is a stronger acid than 5
7 = NEUTRAL – based on pure water
8-14 = Base (alkaline) – the higher the pH, the stronger the base.
Ex. 14 is a stronger base than 11
Enzymes
Enzymes are a special type of protein that speeds up a chemical
reaction by lowering the activation energy of a reaction.
Enzymes are biological catalysts
The material an enzyme works on is called the substrate.
The pocket or groove where the substrate fits into on the
enzyme is called the active site.
Enzymes are named for the substrate that they work with.
Names usually end in –ase.
Enzymes can be “denatured” by a change in temperature or a
change in pH.
Practice Questions
1. A molecule that is found on the surface of most cells is
responsible for communication between the cells. This
molecule is made up of long chains of amino acids and is
specific to each cell type. This molecule is a
A. lipid
carbohydrate
C. DNA strand
D. Protein
B.
2. Which statement best describes the function of a lipid in
a cell?
A. storing
and transmitting heredity
B. forming part of biological membranes
C. forming amino acid chains
D. storing phosphorus
3. Which of the following factors is most likely to affect
the function of an enzyme?
A. catalysts
size of beaker
C. proteins
D. temperature
B.
4. Which of the following statements best describes a
function of an enzyme?
A. All
enzymes work on all substrates.
B. Enzymes are specialized proteins that serve as catalysts.
C. Enzymes are carbohydrate-based molecules in all cells.
D. The structure of enzymes is changed during a chemical
reaction.
5. Which of the following substances would show a positive
brown paper test for lipids?
A. apples
bacon
C. crackers
D. water
B.
6. Which pH indicates a substance that is more basic than a
substance with a pH of 9?
A. 6
2
C. 8
D. 12
B.
7. Which of the following is a list of elements that make up
the structure of a carbohydrate?
A. carbon, nitrogen, oxygen
hydrogen, carbon, oxygen
C. nitrogen, sulfur, oxygen
D. oxygen, carbon, phosphorus
B.
8. Which of the following is a function of proteins?
A. storing
energy
B. storing waste
C. growth and repair
D. breaking chemical bonds
9. Which of the following organic molecule tests is
correctly paired with its organic molecule?
A. proteins
– brown paper
B. glucose – biuret
C. starch - iodine
D. lipid – benedicts
10. Which biomolecules store and transmit genetic
information?
A. carbohydrates
lipids
C. nucleic acids
D. proteins
B.
11. Which of the following best describes the function of
carbohydrates?
A. They
code for proteins.
B. They form biological membranes.
C. They provide a source of energy for an organism.
D. They control reaction rates in a cell.
Biochemistry Unit Review
Part 2
The Cell Theory
The cell theory was developed with the help of the light
microscope.
The cell theory states that:
1. all organisms are composed of cells
2. cells are the basic unit of structure and function in
living things
3. cells come from pre-existing cells
The Cell Theory
Cell Theory People:
a. Anton von Leeuwenhoek  microorganisms
b. Robert Hooke  named cells
c. Matthias Schleiden  all plants made of cells
d. Theodore Schwann  all animals made of cells
e. Rudolph Virchow  new cells come from existing
cells.
Microscopes
Total Magnification = eyepiece
(ocular lens) x objective lens
Eyepiece = 10x
Objectives = 10x, 40x, 65x
Greatest possible magnification
=
Ex. Total magnification 600x =
Eyepiece 10x X Objective
60x
Under the microscope, letters
get put upside down and
backwards.
Ex. “e” appears as “___”.
Types of microscopes:
1. light microscope
2. scanning electron
microscope
3. transmission electron
microscope
Prokaryotes vs. Eukaryotes

Make a Venn diagram using the following words:
Nucleus
Organelles
DNA
Cell membrane
Capsule
Reproduce
Plants
Bacteria
Animals
Eukaryotic Organelles
Nucleus – controls the cell (where DNA is found)
Ribosomes – site of protein synthesis (make proteins)
Plasma (Cell) Membrane – controls what comes in and out
Endoplasmic reticulum– series of channels that act as a
transport system
Golgi Apparatus – packs, sorts, and ships molecules
Mitochondria – powerhouse; makes energy; site of cellular
respiration
Chloroplast – site of photosynthesis
Vacuole – stores water, food and waste
Cell wall – used for structure and support in plant cells
Eukaryotic Organelles
Plant cells are different from animal cells in three ways:
1. plant cells have a cell wall, animal cells don’t
2. plant cells have chloroplasts, animal cells don’t
3. plant cells have larger vacuole
Practice Questions
1. If an organism does not have membrane-bound
organelles, what is it called?
A. simple
eukaryotic
C. prokaryotic
D. complex
B.
2. Which organelle pictured is responsible for transforming
energy?
a.
b.
c.
d.
3. During the period from 1838-1855, German scientists
Matthias Schleiden, Theodor Schwann, and Rudolph
Virchow contributed greatly to the understanding of plant
and animal cells. Their cell theory includes all of the
following ideas except which one?
A. All
living things are made of cells.
B. Cells are the basic units of structure and function of living
things.
C. Cells come from pre-existing cells.
D. Viruses are not made of cells.
4. Prokaryotic and eukaryotic cells are distinguished from
each other by which of the following?
A. Prokaryotic
cells include most cells, other than bacteria,
and lack a nucleus and membrane-bound organelles.
B. Prokaryotic cells include mainly bacteria, and lack a
nucleus as well as membrane-bound organelles.
C. Prokaryotic cells include most cells, other than bacteria,
and contain a nucleus and membrane-bound organelles.
D. Prokaryotic cells include mainly bacteria, and contain a
nucleus as well as membrane-bound organelles.
5. Which of the cell organelles labeled below helps you
determine if this is an animal cell or a plant cell?
A. nucleus
cell wall
C. ribosomes
D. mitochondria
B.
6. What is the function of the Golgi apparatus?
A. manufacture
proteins
B. package and transport proteins
C. store proteins
D. break down proteins to release energy
7. A student identifies an unknown cell as being eukaryotic.
Which of the following did she most likely identify in
order to draw this conclusion?
A. nucleus
cell wall
C. chloroplasts
D. cell membrane
B.
8. Which of the following best describes the function of a
ribosome?
A. making
proteins
B. digesting lipids, carbohydrates and proteins
C. storing water, proteins, salts and carbohydrates
D. providing structural support for the cell
Biochemistry Unit Exam Review
Part 3
Cell Membrane
The cell membrane (plasma membrane) is made up of
two layers of lipids, so it is called a lipid bilayer.
Proteins can also be found inside the membrane. They
can act as receptors, channels and pumps.
Cell Membrane
The lipid bilayer contains phospholipid molecules with
non-polar tails and polar heads.
They hydrophobic tails are “water hating”, while the
hydrophilic heads are “water loving”.
They are arranged in the membrane with the tails
together and the heads on the outside.
Cell Membrane
Most biological membranes are “selectively permeable”,
or some substances can pass across the membrane
while others cannot.
Cell Transport
The selective permeability of the cell membrane is most
closely associated with the maintenance of homeostasis.
Two main types of transport are passive and active.
Passive Transport – does not require energy; moves
molecules from high concentration  low concentration.
Diffusion – molecules move from high  low
Osmosis – water moves from high  low
(water moves from less salt to more salt)
Facilitated Diffusion– large molecules move from high 
low through a transport protein
Cell Transport
Active Transport – requires energy (ATP); moves substances
from low concentration  high concentration.
Equilibrium – the concentration of dissolved substance is
the equal throughout a system.
Cell Transport
What happens to a cell when …
a. it is placed in a solution with a higher salt
concentration –
it will shrink
b. it is placed in a solution with the same salt
concentration
stay the same
c. it is placed in a solution with lower salt
concentration –
it will swell
Photosynthesis
Photosynthesis is the conversion of light into chemical
energy.
Equation: CO2 + H2O + Light  C6H12O6 + O2
Carbon dioxide + Water + light energy  Glucose (sugars) +
oxygen
Photosynthesis occurs in the chloroplast and the sunlight
required for the reaction is absorbed by the chloroplast
pigment chlorophyll.
There are 2 stages to photosynthesis:
1. Light-dependent (Electron Transport Chain)
2. Calvin Cycle (Light-independent)
Aerobic Cellular Respiration
Cellular respiration is the process that releases energy by
breaking down glucose and other food molecules in the
presence of oxygen.
Equation: C6H12O6 + O2  CO2 + H20 + ATP (energy)
Glucose + oxygen  Carbon Dioxide + water + ATP
Cellular respiration occurs in the mitochondria.
The most ATP is made during aerobic cellular respiration
(36 / molecule of glucose)
There are 3 stages to aerobic cellular respiration:
Glycolysis
Kreb’s Cycle
Electron Transport Chain
Anaerobic Cellular Respiration
Anaerobic respiration occurs when there is a lack of
oxygen for the cells.
Anaerobic respiration has 2 stages:
Glycolysis
Fermentation
There are 2 types of fermentation:
Lactic Acid
Forms lactic acid as a waste product.
Lactic acid creates sore muscles after exercising.
Alcoholic
Forms ethanol as a waste product.
Used in making bread, beer & wine.
Practice Questions #3 and #4
1. A cell moves particles from a region of lesser
concentration to a region of greater concentration by
A. active
transport
B. facilitated diffusion
C. osmosis
D. passive transport
2. Which conditions shown below may cause a cell to
burst?
3. What cell process is responsible for the transport shown
below?
A. active transport
B. osmosis
C. facilitated diffusion
D. passive transport
4. Which process does an organism use to move large
molecules into a cell?
A. simple
diffusion
B. exocytosis
C. endocytosis
D. facilitated diffusion
5. Blood plasma and sea water have nearly the same salt
concentration. What will happen to a red blood cell
placed in pure water?
A. it
will swell
B. it will disintegrate
C. it will shrink
D. it will divide
6. Cells have a selectively permeable membrane. What is
the primary purpose of this membrane?
A. to
keep all of the cytoplasm inside the cell
B. to control which materials enter and leave the cell
C. to allow photosynthesis to occur
D. to manufacture proteins
7. Which of the following statements about osmosis and
diffusion is correct?
A. Osmosis
requires energy and diffusion does not.
B. Both osmosis and diffusion involve the movement of
molecules from areas of higher concentration to areas of
lower concentration.
C. Diffusion is the movement of water from areas of higher
concentration to areas of lower concentration.
D. Osmosis is the movement of water from areas of lower
concentration to areas of higher concentration.
8. Which form of transport is represented in the
illustration below?
A. facilitated
transport
diffusion
C. active transport
D. osmosis
B.
9. An animal cell is placed in a solution of distilled water. If
left overnight, this cell will
A. swell
and burst
B. shrivel and die
C. undergo chemosynthesis
D. remain the same, since it has a cell wall to protect it
1. Energy is released from ATP when the bond is broken
between
A. two
phosphate groups
B. ribose and a phosphate group
C. adenine and a phosphate group
D. adenine and ribose
2. How are the processes of photosynthesis and
respiration linked?
A. One
takes place during the day, the other at night.
B. One takes place in animals, the other in plants.
C. The reactants of one are generally the products of the
other.
D. They are identical, but in the reverse order of each other.
3. Which of the following produces the greatest amount of
ATP?
A. gylcolysis
Krebs cycle
C. Electron transport chain
D. fermentation
B.
4. Which of the following statements about photosynthesis
is correct?
A. The
products of photosynthesis are sugar and oxygen.
B. Photosynthesis occurs in mitochondria.
C. Sunlight is not necessary for photosynthesis to occur.
D. The products of photosynthesis are sugar and water.
5. Which of the following is the correct sequence of events
in the process of photosynthesis?
A. Calvin
cycle, electron transport chain, absorption of light
energy.
B. absorption of light energy, Calvin cycle, electron
transport chain
C. electron transport chain, absorption of light energy,
Calvin cycle
D. absorption of light energy, electron transport chain,
Calvin cycle
6. A cell that is capable of carrying out both photosynthesis
and respiration is probably a
A. prokaryotic
mitotic cell
C. plant cell
D. animal cell
B.
cell
7. The equation below summarizes what biological
processes?
Light + 6H20 + 6CO2  C6H12O6 + 6O2 + ATP
A. chemophotosynthesis
fermentation
C. photosynthesis
D. cellular respiration
B.
8. During strenuous exercise, animals cannot take in enough
oxygen to supply their cells with the necessary oxygen.
As a result, they carry out lactic acid fermentation to
supply their cells with the necessary energy. Lactic acid
fermentation is a type of
A. anaerobic
respiration
B. aerobic respiration
C. alcoholic respiration
D. ATP respiration