Biology 20: Module 1: Lesson 2
MODULE 1: LESSON 2 ASSIGNMENT
This Module 1: Lesson 2 Assignment is worth 56 marks. The value of each assignment
and each question is stated in the left margin.
Lesson 2 Assignment: Energy Flow Throug
There are common features in the bone structure of vertebrate limbs despite their varied use
Vertebrate limbs have a lot of uses which require variable amounts of force and different velocities of
Vertebrate limbs share some common characteristi
The fossil record provides evidence for evolution
Evidence to prove evolution can be shown through fossil fuels:
- The layers of fossils appearing matched the way in which they'd be expected to evolve
- The sequence of fossils match the ecology of the gro
The theory of evolution by natural selection was proposed roughly simultaneously by both Charles
Darwin and Alfred Russel Wallace, and set out in detail in Darwin's 1859 book On the Origin of Species.
In the 1930s, Darwinian natural selection was combined
However, when a species is separated into populations that are prevented from interbreeding,
mutations, genetic drift, and the selection of novel traits cause the accumulation of differences over
generations and the emergence of new species.
Over many generations, adaptations occur through a combination of successive, small, random changes
in traits, and natural selection of those variants best-suited for their environment.
In contrast, genetic drift produces random changes in the frequency o
Evolution occurs when these heritable differences become more common or rare in a population, either
non-randomly through natural selection or randomly through genetic drift.
Natural selection is a process that causes heritable traits that are helpful for
In biology, evolution is the change in the inherited traits of a population from generation to generation.
These traits are the expression of genes that are copied and passed on to offspring during reproduction.
Mutations in these genes can produce new or
Some proteins form * channels and pumps to help move material across the cell
B) some proteins *
attach directly to the cytoskeleton (internal support of the cell), enabling cells to respond
to their environment by using their membranes
The properties of lipids
Cell membranes have this typical layered structure because of the chemical properties of
the lipids that make up the membrane.
This *flexible structure forms a strong *barrier between the cell and its surroundings.
The cell membra
One of the most important functions of the cell membrane is to keep the cell's internal
conditions relatively *constant.
In order to maintain this condition of homeostasis, the cell membrane must control the
transport of materials into o
Driven by differences in solute concentration, the net movement of water into or out of a
cell produces a force known as osmotic pressure
Almost always hypertonic
Because cells contain a variety of solutes such as:
Sugars, proteins, salts
Predicting the direction of osmosis in cells
The direction of water movement into or out of a cell can have dire consequences on the
survival of a cell. By knowing the concentrations of solute and solvent on the inside and
outside of a cell, we ca
Introduction to cell transport
Transport is the name of the life process in which materials are exchanged between and
organism and its environment.
What types of materials need to be transported into or out of living cells?
Transport can be as simple as m
the process by which particles move from an area of high concentration to an area of
The process of diffusion drives the movement of many molecules which move across cell
Suppose a substance is present in unequal
What will happen to the concentration gradient over time as diffusion continues?
High gradient low gradient no gradient
Once the concentration of the substance on both sides of the cell membrane is the same
Equilibrium is reached
Particles of the solution will continue to move across the membrane in almost equal
numbers, so there is no further *net change to the concentration of the solutions inside or
outside the cell.
This is defined to in fact
Process in which molecules that cannot directly diffuse across the cell membrane pass
through special protein channels
Red blood cells have protein carriers to allow glucose to pass in/out of the cell.
There are hundreds of exam
A triglyceride, this molecule is composed of glycerol and 3 unsaturated fatty acid chains:
This monosaccharide is used as a reactant in dehydration synthesis to make glycogen,
starch or cellulose: glucose
A general term for a molecule composed of two
Structure of fats and oils/ triglycerides:
Composed of 1 glycerol + 3 fatty acids
Fats and oils differ in the types of fatty acids found in the triglycerides
Glycerol: c3 h8o3
Fatty acid #3
Two types of fatty acid chains:
Saturated fatty acid chains
Structure of an amino acid:
Central carbon atom (-c-)
Amino group (-nh2)
always the same
1 hydrogen atom (-h), R group- one of 20 different side chains , Changes (variable),
Examples of amino acids: , #1 glycine (gly), #2 methionine
The repeating units are called: monomers (single lego block)
Two monomers joined together are called: dimer (2 lego blocks)
Large compounds composed of many monomers are called: polymer
(50, 500, 50,000, large amounts of lego blocks)
Nucleic acids contain carbon, hydrogen, oxygen, nitrogen, phosphate
[c, h, o, n, p]
Structural units of nucleic acids:
Nucleotides: (monomer) sugar + poy (phosphate group) + nitrogen base (adenine/
cyosire/ guanine/ thymine)
Two important n
Monomer unit of a carbohydrate: simple sugar, monosaccharide
Glucose, fructose, galactose, and ribose
Glucose, fructose, galactose all have same chemical formula: c6h12o6
Dissolves easily in water
Lipids- brown paper bag test
Proteins: biuret solution
Two major types of compounds found in living things:
Usually do not contain carbon (does include co2)
Usually originate in the abiotic or non-living
Can be found in living things
Examples: o2 h2o nacl nh3 h2o2
Important polysaccharides synthesized by living things:
-animals-consume plant stanches, digest them (hydrolysis) and synthesize:
Glycogen-energy storage molecule (branched/ granules in potato tuber cells)
-plants- produces glucose during photosynthesis a
Fats vs Oils
Words: solid, double, saturated, liquid, straight, unsaturated, bent, single
Fatty acid chains
Type of carbon to carbon bonds
Shape of fatty acid chains
State of matter at room temp.
Biochemistry study guide
Organic vs. Inorganic molecules:
Anything but carbon.
C, h, o carbs and lipids
Except carbon dioxide.
C, h, o, n proteins
Water, nacl, oxygen gas
C, h, o, n, p nucleic acids
Is it pr