Download Cell Processes and Energy

Question: In the photosynthesis equation, what does the arrow represent?
PHOTOSYNTHESIS
Nearly all living things obtain energy either directly or indirectly from the energy
of sunlight captured during photosynthesis.
Photosynthesis — process by which a cell captures energy in sunlight and uses it to
make food.
Plants such as grass, use energy from sun to make its own food, therefore it’s called
an autotroph.
The caterpillar obtains energy from eating grass and the bird obtains energy by
feeding on caterpillar. These organisms which cannot make their own food are called
heterotrophs.
During photosynthesis, autotrophs use the sun’s energy to convert carbon dioxide
(CO 2) and water (H 2O) into oxygen (O2) and sugars (C6 H12 O6):
sunlight
6 CO2 + 6 H2O
C6 H12 O6 + 6 O2
energy
TWO STAGES OF PHOTOSYNTHESIS
STAGE 1
STAGE 2
CAPTURING SUN’S ENERGY
USING ENERGY TO MAKE FOOD
 Process occurs mostly in leaves
 Cells need H2O and CO2 for this stage.
CO2 enters leaves through stomata,
H2O enters through roots.
 CO2 and H2O undergo chemical
reaction in chloroplasts to produce
sugars (C6H12O6) and oxygen which
exit leaves through stomata.
 Chloroplasts in plant cells captive
energy using photosynthetic pigment
called chlorophyll
 Energy powers stage 2
Question: What does bread have to do with fermentation?
Question: Cytokinesis occurs during which stage of mitosis?
CELLULAR RESPIRATION
CELL CYCLE
Respiration — process by which cells obtain energy from glucose by breaking down
simple
molecules
suchof
ascells
sugar,
stored which
energy.is part of the
At
thisfood
moment,
millions
in and
the releasing
body are the
dividing,
process in the cell cycle.
*Cellular respiration is different than the term “respiration” which is used for
breathing.
Cell cycle — regular sequence of growth and division that cells undergo which is
divided into three main stages: interphase, mitosis and cytokinesis.
THE RESPIRATION EQUATION
STAGE 1: INTERPHASE
This
is the
cell grows, makes a copy of its
C6 H12
O6 +period
6 O2 before cell division
6 CO2 +where
6 H2Othe
+ energy
DNA, and prepares to divide into two cells.
sugar
oxygen
carbon water
dioxide
STAGE 2: MITOSIS
comes
from which
comes from
*Notice
equation
is new nuclei — one copy of
Stage during
the cell’s nucleus
divides
into two
foodDNA
we eat
air or water
opposite
that of cells.
the
is distributed
into each of the
two daughter
during respiration
photosynthesis
*Mitosis is divided into four phases: PROPHASE, METAPHASE, ANAPHASE and
TELOPHASE.
Two Stages of Cellular Respiration:
STAGE 3: CYTOKINESIS
Final stage in which the cytoplasm divides and the organelles are distributed into
Stage
1:the
In the
broken
downTELOPHASE
into smaller of
molecules;
each of
twocytoplasm,
new cells. (glucose
Usuallyisbegins
during
mitosis) oxygen
is NOT involved and only a small amount of energy is released.
Stage 2: Takes place in the mitochondria — there molecules are broken down even
Animal
Plant
Cells require oxygen (O2) and
further Cells
by chemical reactions. These chemical
reactions
release a great deal of ENERGY. CO2 and H2O are also released — in most animals
Cell
squeezes
thesemembrane
two products
leavetogether
body by around
exhaling. Cell plate forms across middle of cell
middle of cell, pinching cytoplasm into
gradually developing into new cell
two
new
cells
membrane.
Fermentation — provides energy for cells without
using oxygen. For example,
alcoholic fermentation. Used in baking or lactic acid. Fermentation felt in muscles
after extreme exertion.
Question: What is PMAT?
PHASES OF MITOSIS
Mitosis is a continuous process, however biologists have divided the mitotic
phase into four main stages: prophase, metaphase, anaphase and telophase.
PROPHASE
 The first and longest phase in which the chromatin bundles up to form
chromosomes in the nucleus. Each chromosome consists of a pair of sister
chromatids joined at the centromere.
 Nucleolus disappears, cells stop making ribosomes and a football-shaped
structure called the mitotic spindle forms which start tugging chromosomes
toward center of cell.
METAPHASE
 A brief, second phase of mitosis where all the chromosomes are pulled to the
center of the cell.
ANAPHASE
 Third stage where sister chromatids separate and each chromatid is now
considered a “daughter”
 Spindles begin to shorten pulling the split chromatids toward opposite ends
(or poles) of the cell.
TELOPHASE
 Final stage where chromatids move to opposite sides of the cell and two new
nuclei are formed — one on each side of cell. Two daughter cells are formed
when a new double membrane forms allowing cytoplasm to divide and
separate by CYTOKINESIS.
Question: The shape of a DNA molecule is called a what?
DNA STRUCTURE AND REPLICATION
DNA (Deoxyribonucleic acid) — genetic material that carries information about
an organism from one generation to the next.
DNA is found in the chromatin in the nucleus.
A DNA molecule looks like a twisted ladder, which is made up of units called
nucleotides. Each nucleotide is made up of three components: a 5-carbon sugar
called deoxyribose, and a phosphate group which make up the “sides” of the
ladder, and a nitrogen base which make up the “rung” of the ladder.
DNA has four kinds of nitrogen bases: adenine, thymine, guanine, and cytosine.
Note: Adenine ONLY pairs with Thymine, while Guanine ONLY pairs with
Cytosine
During DNA replication, a DNA molecule “unzips” between its paired bases. New
bases pair up with bases on old strand forming two identical DNA strands.
Question: What does SPF stand for on suntan lotion bottles?
CONTROL SYSTEM OF CELL CYCLE
A “control system” made of certain proteins within a cell directs the timing and
sequence of events of the cell cycle. If something goes wrong in this system, cells
lose control of cell cycle.
Cancer — a disease caused by a disruption to the cell cycle leading to uncontrolled
cell division.
Cancerous cells form masses of tissues called tumors.
Benign tumor — abnormal mass of essentially normal cells that always remain at
original site of growth and can usually be removed with surgery.
Malignant tumor — mass of cancerous cells that displace normal tissue as it
grows. If not killed or removed, this tumor can spread into surrounding tissue,
or worse, break off and travel to other parts of the body. The spreading of cancer
is called metastasis.
Causes of cancer can either be environmental, such as cigarette smoke, oil and
water pollution or ultraviolet radiation from the sun. Cancer can also be caused
by a genetic factor such as viral infections that damage genes.
Treatment of cancer includes radiation therapy and chemotherapy which both
disrupt cell division.