Transcript Goal 2

Goal 2
The learner will develop an
understanding of the physical,
chemical, and cellular basis of life
Main Topics
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Organic Compounds
Structure and Function of Cells
Organelles
Cell Specialization and Communication
Cell Transport
Enzymes
Cellular Respiration and Photosynthesis
Organic Compounds
• 4 organic compounds
– “organic” = contains carbon = all living things
have organic compounds in them
– Carbohydrates
– Lipids
– Proteins
– Nucleic Acids
Carbohydrates (Polysaccharides)
• Subunit (made of) = monosaccharides
• Function = immediate energy
• Examples:
– Starch = energy storage for plants
– Cellulose = makes up cell walls
– Glycogen = energy storage for animals
– Glucose = a simple sugar
Carbs Cont’
• Tests =
– Starch is tested with
iodine
– Monosaccharides
are tested with
Benedicts Solution
Lipids
• Subunits = glycerol and fatty acids
• Function = long term energy storage
• Examples:
– Fats
– Waxes on plants (cuticle)
• Tests = brown paper bag test
Proteins
• Subunits = amino acids
• Function = structure of tissues, transport
for cells
• Examples:
– Insulin (hormones)
– Hemoglobin (red blood cells)
– Enzymes
– Antigens/Antibodies
• Test = Biuret’s Reagent
Enzymes
• Speed up chemical reactions = catalysts
• Can be affected by pH or temperature =
enzymes are very specific!
• Enzymes are reusable!
Lock and Key
Nucleic Acids
• Subunits = nucleotides
• Function = stores cellular information for
cells
• Examples:
– DNA and RNA
• Tests = NONE… all living things have DNA
and RNA
Cell Organelles
• Nucleus = controls cell activity “brain”
• Plasma Membrane (aka cell membrane) =
controls what enters and exits cell “gate
keeper”
• Cell Wall = protects and supports some
cells
• Mitochondria = provides energy (ATP) to
cells “powerhouse”
Organelles, cont’
• Vacuoles = stores water, waste, food
• Chloroplast = site of photosynthesis,
makes food for plant cells
• Ribosome = site of protein synthesis –
where proteins are made
Microscope
• Total Magnification:
– Ocular lens x objective lens
– Ex:
• The microscope you are using has an ocular lens
of 10x. The objective lens is on 60x. What is the
total magnification?
Organization
• Unicellular = made of 1 cell (bacteria)
• Multicellular = made of many cells (us,
plants, animals)
• Cells  Tissues  Organs  Organ Systems  Organism
Plant Cells
Animal Cells
• Have cell walls made
of cellulose outside of
cell membrane
• Have chloroplasts
and mitochondria
• Boxy shape
• Green
• 1 big vacuole
• No cell walls; just a
cell membrane
• Mitochondria only
• Round shape, more
flexible
• Centrioles
• Many small vacuoles
Cell Communication
• Chemical signals can be
released by one cell to
influence another cell
– Ex: Hormones
• Chemicals attach to receptor
proteins on cells and pass
the message along
Cell Transport
• Cells must maintain homeostasis
• Homeostasis = maintaining a stable internal
environment
– Regulate temperature = shiver or sweat
– Blood glucose = insulin is released after
eating
– Water = mouth becomes dry when thirsty,
eliminate water by urine
Cell Membrane
• The cell membrane maintains
homeostasis in a cell by allowing only
certain things in and certain things out!
– Semi-Permeable or Selectively Permeable
• Structure = phospholipid bilayer
Two Types of Transport
• Passive Transport
– NO ENERGY NEEDED
– Goes from HIGH concentrations to LOW
concentrations
– Ex: Diffusion and Osmosis, Faciliated Diffusion
• Active Transport
– ENERGY is NEEDED!!
– Goes from LOW concentrations to HIGH
concentrations
Diffusion - PASSIVE
• Diffusion = the movement of PARTICLES
(solutes) from an area of high
concentration to low concentration
• Concentration Gradient = when the sides
are not equal
Osmosis - PASSIVE
• Osmosis = the movement of WATER from
an area of high concentration to an area of
low concentration
Water
Cells and Osmosis
• Water goes into cell = causes swelling
• Water leaves cell = causes shrinking
Osmosis Examples
• A cell is placed in a solution where there is
20% water outside and 80% water inside.
Where does the water go? What happens
to the cell?
• A cell has 40% glucose outside and 60%
glucose inside. What happens?
Facilitated Diffusion - PASSIVE
• Facilitated Diffusion = diffusion through
transport proteins
• Two proteins
– Channel = does not change shape
– Carrier = changes shape
ACTIVE Transport
• Active Transport = requires ENERGY!
• Can use carrier proteins
Active Transport, Cont’
• Endocytosis and Exocytosis are examples
of active transport = require ENERGY
– Endo- = taking IN of large molecules
– Exo- = EXPELLING of large molecules
Cell Energy
• ATP is the source of energy for cells
– ATP = A-P-P-P
– ADP = A-P-P
• ATP becomes ADP by: losing a P =
releases energy
• ADP becomes ATP by: gaining a P =
stores energy
Cell Energy
Photosynthesis
- Occurs in chloroplast
- Occurs in plants
- Makes food for plants
CO2 + H2O + light  C6H12O6 + O2
** after plants make food in
photosynthesis, the food is turned
into energy during cellular
respiration!
Cellular Respiration
- Occurs in
mitochondria
- Occurs in plants AND
animals
- Turns food into
energy (ATP)
C6H12O6 + O2  CO2 + H2O+ ATP
Cellular Respiration
Aerobic
- Occurs in mitochondria when oxygen is available
- Makes 36 ATPs 
Anaerobic
- Occurs in mitochondria when oxygen is NOT available
- Makes 2 ATP 
- AKA Fermentation
- 2 types: Alcoholic (makes Alcohol and CO2 – bread, beer) and
Lactic Acid (makes lactic acid in your muscles)
A student tested different foods to determine
which organic compounds were
present. She based her results on the
following information:
All four tests were performed on skim milk. The
observations were that Benedict’s solution
changed color and Biuret’s changed color.
All other tests had a negative result.
Which organic compounds were present
in skim milk?
A.
B.
C.
D.
Sugar and Protein
Fat and Sugar
Sugar and Starch
Starch and Protein
Test
Positive
Reaction
Organic
Compound
Indicated
Brown paper
Shiny spot
fat
Benedict’s
Solution
Color change
Sugar
iodine
Color change
starch
Biuret’s
solution
Color change
protein