Download Molecular Biology Study Guide Powerpoint

Molecular Biology
What is molecular biology?
-Molecular biology is the study of biology at a molecular
level.
-The field overlaps with other areas of biology, particularly
genetics and biochemistry.
-Molecular biology chiefly concerns itself with
understanding the interactions between the various systems
of a cell.
Is this an animal or plant cell? Explain.
“Cell Structure & Function” 10:36
Plant Cell: How do plant and animal cells differ?
Organelles have specific functions.
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Lysosome: contains enzymes that break down nutrients, wastes, bacteria and worn
out cell parts
Ribosome: take information from DNA and use it to make proteins
Vacuole: a membrane-bound sac that plays roles in intracellular digestion and the
storage and release of cellular waste products
Nucleus: a large, oval structure that directs all of the cell’s activities; houses
genetic material
Mitochondria: produce most of the energy/ATP the cell needs to carry out its
functions; where respiration occurs
Golgi Body (apparatus): receives and packages products, including proteins, for
use in the cell
Endoplasmic Reticulum: where chemical reactions take place; a system whose
functions include synthesis and transport of lipids and, in regions
where ribosomes are attached, of proteins
Cell Membrane: forms the outside boundary that separates the cell from its
environment; controls what enters and leaves the cell
Cytoplasm: the region between the cell membrane and the nucleus
- Gizmo: “Cell Structure”
Cell Wall: plant; rigid structure that gives the cell shape
- Matching activity
What is “food”?
• material or molecules that provide living things with
the nutrients they need for energy and growth
Foods with natural sugars (carbs)
tend to be the healthiest for you.
And Carbohydrates
(simple & complex carbs)
Food provides molecules that serve as fuel and building
material. (see compound PowerPoint)
• What is a molecule? The smallest particle of a
substance that retains the chemical and physical
properties of the substance and is composed of two
or more atoms; a group of like or different atoms
held together by chemical forces.
The substance (compound) here is water. It is made
up of oxygen (1 atom) and hydrogen (2 atoms). H O
2
(chemical formula for 1 molecule of water)
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Water is a polar molecule because
it has electrically/oppositely charged areas.
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Water is not considered “food” because
it does not provide the body with energy.
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What “biological compounds do our cells need?
The four major biological compounds are:
• Proteins (key for building body tissues; aim for 10% to 35%
of calories)
• Nucleic Acids (RNA and DNA)
• Carbohydrates (fuels our brain and muscles; energy source
- aim for 45% to 65% of calories)
• Lipids (contributes essential fatty acids and promotes
absorption of fat-soluble vitamins A,D,E, and K; energy
source – aim for 20% to 35% of calories – mostly
unsaturated)
- Only proteins, carbohydrates and lipids are considered “food” because they are the only
ones in which the body/cells get energy.
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http://www.youtube.com/watch?v=H8WJ2KENlK0 “Biological Molecules: You are what you eat.” 14:09
What is “protein”?
• One of the three nutrients used as energy sources
(calories) by the body.
• Proteins are essential components of the muscle,
skin, and bones.
• aim for 10% to 35% of calories
• Proteins and carbohydrates each provide 4 calories
of energy per gram, whereas fats provide 9 calories
per gram.
Top 10 Plants High in Protein
#1 asparagus
#5 oats
#8 spinach
#2 pumpkin seeds
#3 cauliflower
#6 beans
#9 broccoli
#4 peanuts
#7 almonds
#10 quinoa
Simple vs Complex Carbs
Carbohydrates and fats are the main source of energy for your body. Carbs are made up of
sugars, which break down to provide either quick energy or slow-burning, sustained energy over a
period of several hours. "Simple" carbs are quick energy sources, while "complex" carbs provide
longer-lasting energy. In addition to providing physical energy, carbohydrates also effectively fuel
the brain.
What are lipids/fats?
• a biological compound that is not soluble (dissolvable) in water, e.g. a fat.
• Fats are classified as “saturated ” or “unsaturated .
• Unsaturated fats are more beneficial to our body and are liquid at room
temperature.
• Saturated fats are less beneficial to our bodies and are solid at room temperature.
• “Trans Fats” are a type of unsaturated fat that is not beneficial to our bodies.
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Lipids/fats have more energy; however, unsaturated fats are healthy.
The Real Story on Fats! 
Are fats good or bad for you?
What do you think?
Unsaturated Fats
VS
Saturated Fats
Effects of Long-term Consumption of Saturated Fats
- Eating fatty foods appears to take an
almost immediate toll on both
short-term memory and exercise
performance.
- Studies have suggested that long-term
consumption of a high-fat diet is
associated with weight gain, heart
disease and declines in cognitive
(mental) function.
- New research shows how indulging in
- fatty foods over the course of a few
- days can affect the brain and body long before
the extra pounds show up.
Plants and Food Production
• The three major functions that are basic
to plant growth and development are:
(O2)
(CO2)
(H2O)
• Photosynthesis – The process of
capturing light energy and converting it
to sugar energy, in the presence of
chlorophyll using carbon dioxide and
water. (releasing O2 and H2O)
• Respiration – The process of
metabolizing (burning) sugars to yield
energy for growth, reproduction, and
other life processes. (releasing H2O and
CO2)
• Transpiration – The loss of water vapor
through the stomata of leaves.
“Respiration & Excretion” 9:16
In photosynthesis…
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carbon dioxide from the air and water from the
soil react with the sun’s energy to form sugars,
starches, proteins, and carbohydratesand release
oxygen as a byproduct.
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the plant uses water and nutrients from the soil,
and carbon dioxide from the air with the sun’s
energy. Oxygen is released as a byproduct.
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Photosynthesis literally means to put together
with light. It occurs only in the chloroplasts, tiny
sub cellular structures contained in the cells of
leaves and green stems.
The chemical equation for photosynthesis is:
6CO2 + 6H2O+ light energy = C6H12O6 + 6O2
The word equation for photosynthesis is:
carbon dioxide + water + light energy =
glucose + oxygen
Respiration in Plants
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In respiration, plants (and animals) convert the sugars back into energy for growth and other
life processes (metabolic processes).
A simple chemical equation for respiration is given below. Notice that the equation for
respiration is the opposite of that for photosynthesis.
The word equation for aerobic respiration is:
glucose + oxygen = carbon dioxide + water + energy
The chemical equation is:
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C6H12O6 + 6O2 = 6CO2 + 6H2O + 2900 kj
Chemically speaking, the process is similar to the oxidation that occurs as wood is
burned, producing heat. When compounds combine with oxygen, the process is
often referred to as “burning”, for example, athlete’s “burn” energy (sugars) as they
exercise. The harder they exercise, the more sugars they burn so the more oxygen
they need. That is why at full speed, they are breathing very fast. Athletes take in
oxygen through their lungs.
At night, plants take in a small amount of oxygen through the stomata in their
leaves and through their roots.
Do plants take in oxygen (O2)?
• All plants and animals on earth engage in a process called respiration.
• One of the byproducts of respiration is carbon dioxide. In other words, respiration
is the opposite of photosynthesis.
Respiration
• Respiration doesn’t depend on light; it goes on 24 hours a day, so that plants and
animals have enough energy to perform the basic functions that keep them alive.
• However, during the day, the amount of oxygen plants release as part of
photosynthesis makes the amount of oxygen they consume for respiration at night
seem negligible.
Nighttime Battle?
• At night, when photosynthesis can’t take place, plants continue to consume oxygen
but they don’t release any back into the atmosphere.
• The amount of oxygen the plants use at night is trivial.
Comparing Photosynthesis and Respiration
Photosynthesis
Respiration
- Produces sugars from light
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energy
Stores energy
Occurs only in cells with
chloroplasts
Releases oxygen
Uses water
Uses carbon dioxide
Requires light
What are the waste products of
photosynthesis? (dissolved O2 demo.)
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Burns sugars for energy
Releases energy
Occurs in most cells
Uses oxygen
Releases water
Produces carbon dioxide
Occurs in darkness and light
What are the waste products of
respiration?
(Yeast Respiration lab)
Transpiration in Plants
- Water in the roots is pulled
through the plant by
transpiration (loss of water
vapor through the stomata
of the leaves).
- Transpiration uses about
90% of the water that
enters the plant. The other
10% is an ingredient in
photosynthesis and cell
growth.
The capillary action of water molecules keep
water moving up the roots and through the plant.
Transpiration
After securing the bag on the plant, water is captured as it travels out the leaves of the
plant..
1. What is the process that leads to transpiration?
2. What are the waste products of photosynthesis?
What is “chemical energy”?
• Consider the ability of your body to do work.
• The glucose (blood sugar) in your body is said to
have "chemical energy" because the glucose
releases energy when chemically reacting
(combusting) with oxygen.
Food provides molecules that serve as fuel and building material for
all organisms.
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Plants use the energy in light to make sugars out of carbon dioxide and water through a
process called photosynthesis.
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This process transforms light energy from the sun into stored chemical energy. Chemical
energy is transferred from one organism in an ecosystem to another as they interact with
each other for food.
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Minerals and other nutrients from soil are not food
(They don’t provide energy.), but are needed for
plants to make complex molecules from the sugar
they make.
Matter is transferred among organisms.
• Molecules from food react with oxygen to produce carbon dioxide (CO2) and water
in a process called cellular respiration.
• Through the process of cellular respiration, cells convert energy (glucose) to a
usable form of energy (ATP).
• Energy stored in ATP enables cells to grow, develop, repair organisms, locomotion
and transportation of molecules across the cell membrane.
• Some plants (like legumes - i.e. peas) form a relationship with microorganisms. This
happens in their roots, and nodules are formed. These microbes can take nitrogen
from the air (which is about 80% nitrogen) and turn it into ammonia, which is
absorbed by the plant’s root.
• Animals get nitrogen by eating other plants or animals, which contain protein
(which is made of nitrogen and other things). Nitrogen is a component in both
protein and chlorophyll.
In plant and animals, molecules from food:
(1) react with oxygen to provide energy that is needed
to carry out life functions;
(2) build and become incorporated into the body
structure or
(3) are stored for later use.
Food is the “fuel” for our bodies. How do animals convert food to
energy?
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Mitochondria are the converters; they convert the fuel into useable energy.
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When food is digested, or broken down into its smallest molecules and nutrients,
and air is taken in, the smallest molecules and nutrients cross into the
bloodstream. These molecules and nutrients include things such as glucose (a
sugar molecule derived from carbohydrates) and oxygen.
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You will consume more fuel than is necessary to make the machine called your
body function. The excess gets stored for later as fat.
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Just as fire burns oxygen and gives off carbon dioxide and water, mitochondria act
like furnaces when they convert glucose into adenosine triphosphate (ATP): They
“burn” (use) oxygen and give off carbon dioxide and water in a process called
respiration. Because the process uses oxygen, it is said to be aerobic (as in aerobic
exercise).
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This chemical process of respiration occurs in every cell, so it is called aerobic
cellular respiration.
What is metabolism?
• Metabolism is the energy (calories) your body needs to function, and it operates
at a different rate for each person.
• This involves a set of chemical reactions that store fuel (food) molecules and
convert them into energy. In order for the body to use the fuel energy stored in
food, the food must first be digested and combined with oxygen (oxidized).
Three factors contribute to the overall metabolic rate of the body.
1. Basal Metabolic Rate (BMR) accounts for about 60% of all energy
used by the body.
2. Daily physical activities account for another 30% of the energy used
by the body.
3. 10% of the energy used by the body is used to digest and process
(oxidize) food.
ENERGY IN = ENERGY OUT
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In order for energy balance to occur, caloric intake equals caloric
output.
What happens to food components (protein, fat/lipids,
carbohydrates taken into the body:
They can be used to fuel metabolic activities and physical
activities.
They can be incorporated into growing body tissues.
They can be stored as fat.
What affect does exercise have on metabolism?