Biological systems utilize free energy and molecular building blocks to grow, to reproduce, and to maintain dynamic homeostasis.
All living systems require energy and matter to grow reproduce and maintain their order. Organisms have different strategies to capture the energy necessary for survival. Autotrophic cells capture sunlight through photosynthesis and chemosynthesis. This energy is used to produce carbohydrates from carbon dioxide. Chemosynthesis obtains energy from inorganic chemicals. Cellular respiration as well as fermentation harvest energy from sugars to produce free energy carriers (ATP). This energy present in sugar drives metabolic pathways in cells.
Organisms must exchange matter like water, nutrients and oxygen with the environment. These can be used to synthesize new molecules and in the process of cellular respiration. Differences in surface-to-volume ratios affect the capacity of a biological system to obtain resources and eliminate wastes. Programmed cell death (apoptosis) plays a role in normal development and differentiation (e.g. morphogenesis). Membranes allow cells to create and maintain internal environments that differ from external environments. The structure of cell membranes results in selective permeability; the movement of molecules across them via osmosis, diffusion and active transport maintains dynamic homeostasis
Eukaryotic cells have specialized internal membranes that separate the cell into regions for a more efficient operation. Each of these regions enables the localization of chemical reactions. Homeostasis helps organisms to respond to changes in the external or internal environment, depending on the feedback. Changes like availability of resources in a biological system influence responses and activities. Plants and animals, defense mechanisms against disruptions and dynamic homeostasis have evolved. The timing and coordination of physiological, developmental and behavioral events are regulated to ensure survival of populations.
Enduring understanding 2.A: Growth, reproduction and maintenance of the organization of living systems
require free energy and matter.
Living systems require energy to maintain order, grow and reproduce. In accordance with the laws of thermodynamics, to offset entropy, energy input must exceed energy lost from and used by an organism to maintain order. Organisms use various energy-related strategies to survive, these include: different metabolic rates, Physiological changes, and variations in reproductive and offspring-raising strategies. The energy deficiency can disrupt the ecosystem. Some organism can capture, use and store free energy. Cells capture energy through photosynthesis and chemosynthesis. Autotrophs capture it from the environment, whereas heterotrophs capture energy from carbon compounds produced by others. Photosynthesis traps free energy in is used to produce carbohydrates from carbon dioxide and water. Cellular respiration and fermentation use free energy available from sugars and from interconnected, multistep pathways (glycolysis, the Krebs cycle and the electron transport chain) to phosphorylate ADP, producing the most common energy carrier, ATP. The free energy available in sugars can be used to drive metabolic pathways vital to cell processes. Photosynthesis and cellular respiration are interdependent in their reactants and products. Organisms must exchange matter with the environment to grow, reproduce and maintain organization. Water and nutrients are essential for building new molecules.
Essential knowledge 2.A.1 : All living systems require constant input of free energy
a. Life requires a highly ordered system.
Evidence of student learning is a demonstrated understanding of each
1. Order is maintained by constant free energy input into the system.
Activities such as growing, reproducing, and moving require energy. Energy is transformed when it is exchange. Plants absorb sunlight and they convert it to sugars, when and animal eats the plant it will use the sugars for fuel. They convert the chemical energy to kinetic energy. This process keeps going and some of the energy present in the system is lost as heat. Energy usually enters the system as light and is released as heat.
2. Loss of order or free energy flow results in death.
Systems are highly ordered and disorder can cause the death of many organisms. Plants and other photosynthetic organisms are producers; they take the sunlight and convert it into sugars. Consumers need producers in order to obtain the energy necessary for all of their activities, and if there are not producers in an environment, the consumers will die. If organisms do not have energy they die.
3. Increased disorder and entropy are offset by biological processes that maintain or increase order.
According to the law of thermodynamics, energy flow must be bigger than the energy lost as heat. This is needed to maintain the order in a system. Some organisms have energy strategies to survive, like different metabolic rates, physiological changes, and some variations in reproduction. The energy deficiency can disrupt the ecosystem, and some organisms have
Organisms must exchange matter like water, nutrients and oxygen with the environment. These can be used to synthesize new molecules and in the process of cellular respiration. Differences in surface-to-volume ratios affect the capacity of a biological system to obtain resources and eliminate wastes. Programmed cell death (apoptosis) plays a role in normal development and differentiation (e.g. morphogenesis). Membranes allow cells to create and maintain internal environments that differ from external environments. The structure of cell membranes results in selective permeability; the movement of molecules across them via osmosis, diffusion and active transport maintains dynamic homeostasis
Eukaryotic cells have specialized internal membranes that separate the cell into regions for a more efficient operation. Each of these regions enables the localization of chemical reactions. Homeostasis helps organisms to respond to changes in the external or internal environment, depending on the feedback. Changes like availability of resources in a biological system influence responses and activities. Plants and animals, defense mechanisms against disruptions and dynamic homeostasis have evolved. The timing and coordination of physiological, developmental and behavioral events are regulated to ensure survival of populations.
Enduring understanding 2.A: Growth, reproduction and maintenance of the organization of living systems
require free energy and matter.
Living systems require energy to maintain order, grow and reproduce. In accordance with the laws of thermodynamics, to offset entropy, energy input must exceed energy lost from and used by an organism to maintain order. Organisms use various energy-related strategies to survive, these include: different metabolic rates, Physiological changes, and variations in reproductive and offspring-raising strategies. The energy deficiency can disrupt the ecosystem. Some organism can capture, use and store free energy. Cells capture energy through photosynthesis and chemosynthesis. Autotrophs capture it from the environment, whereas heterotrophs capture energy from carbon compounds produced by others. Photosynthesis traps free energy in is used to produce carbohydrates from carbon dioxide and water. Cellular respiration and fermentation use free energy available from sugars and from interconnected, multistep pathways (glycolysis, the Krebs cycle and the electron transport chain) to phosphorylate ADP, producing the most common energy carrier, ATP. The free energy available in sugars can be used to drive metabolic pathways vital to cell processes. Photosynthesis and cellular respiration are interdependent in their reactants and products. Organisms must exchange matter with the environment to grow, reproduce and maintain organization. Water and nutrients are essential for building new molecules.
Essential knowledge 2.A.1 : All living systems require constant input of free energy
a. Life requires a highly ordered system.
Evidence of student learning is a demonstrated understanding of each
1. Order is maintained by constant free energy input into the system.
Activities such as growing, reproducing, and moving require energy. Energy is transformed when it is exchange. Plants absorb sunlight and they convert it to sugars, when and animal eats the plant it will use the sugars for fuel. They convert the chemical energy to kinetic energy. This process keeps going and some of the energy present in the system is lost as heat. Energy usually enters the system as light and is released as heat.
2. Loss of order or free energy flow results in death.
Systems are highly ordered and disorder can cause the death of many organisms. Plants and other photosynthetic organisms are producers; they take the sunlight and convert it into sugars. Consumers need producers in order to obtain the energy necessary for all of their activities, and if there are not producers in an environment, the consumers will die. If organisms do not have energy they die.
3. Increased disorder and entropy are offset by biological processes that maintain or increase order.
According to the law of thermodynamics, energy flow must be bigger than the energy lost as heat. This is needed to maintain the order in a system. Some organisms have energy strategies to survive, like different metabolic rates, physiological changes, and some variations in reproduction. The energy deficiency can disrupt the ecosystem, and some organisms have
Enduring understanding 2.C: Organisms use feedback mechanisms to regulate growth and reproduction, and to maintain dynamic homeostasis.
Organisms respond to changes in their internal and external environments through behavioral and physiological mechanisms. Organisms use negative feedback mechanisms to maintain their internal environments by returning the changing condition back to its target set point, while positive feedback mechanisms amplify responses.
Essential knowledge 2.C.2: Organisms respond to changes in their external environments.
a. Organisms respond to changes in their environment through behavioral and physiological mechanisms.
Taxis and kinesis in animals:
In changing locations, some animals rely on kinesis, a change in activity or turning rate in response to a stimulus. In contrast to a kinesis, a taxis is an orientated movement toward (positive taxis) or away from (negative taxis) some stimulus.
Essential knowledge 2.C.2: Organisms respond to changes in their external environments.
a. Organisms respond to changes in their environment through behavioral and physiological mechanisms.
Taxis and kinesis in animals:
In changing locations, some animals rely on kinesis, a change in activity or turning rate in response to a stimulus. In contrast to a kinesis, a taxis is an orientated movement toward (positive taxis) or away from (negative taxis) some stimulus.
Enduring understanding 2.D. Growth and dynamic homeostasis of a biological system are influenced by changes in the system’s environment.
a. Cells activities are affected by the interactions with biotic and Abiotic factors.
-Temperature: It is an important factor in the distribution of organisms because of its effect on biological processes. Cells may rupture if the water temperature they contain freezes (below 0ºC), though extraordinary adaptations enable some organisms, such as therrmophilic prokaryotes to live outside the temperature range habitable by other life.
-Water availability: A dramatic variation in water availability among habitants is another important factor in species distribution. Species that living at the seashore or in tidal wetlands can desiccate as the tide moves away. Desert organisms, for example, exhibit a variety of adaptations acquiring and conserving water in dry environments.
-Sunlight: Sunlight is important because it provides energy to the photosynthetic organisms, and the lack of it can cause little distribution of these species. Too much light can also limit the survival of the organisms. The atmosphere is thinner at higher elevations, absorbing less ultraviolet radiation, so the sun’s rays are more likely to damage DNA and proteins.
b. Organism activities are affected by interactions with biotic and Abiotic factors.
- Salinity and pH: The salt concentration of water in the environment affects the water balance of organisms through osmosis.
-Temperature: It is an important factor in the distribution of organisms because of its effect on biological processes. Cells may rupture if the water temperature they contain freezes (below 0ºC), though extraordinary adaptations enable some organisms, such as therrmophilic prokaryotes to live outside the temperature range habitable by other life.
-Water availability: A dramatic variation in water availability among habitants is another important factor in species distribution. Species that living at the seashore or in tidal wetlands can desiccate as the tide moves away. Desert organisms, for example, exhibit a variety of adaptations acquiring and conserving water in dry environments.
-Sunlight: Sunlight is important because it provides energy to the photosynthetic organisms, and the lack of it can cause little distribution of these species. Too much light can also limit the survival of the organisms. The atmosphere is thinner at higher elevations, absorbing less ultraviolet radiation, so the sun’s rays are more likely to damage DNA and proteins.
b. Organism activities are affected by interactions with biotic and Abiotic factors.
- Salinity and pH: The salt concentration of water in the environment affects the water balance of organisms through osmosis.
Essential knowledge 2.E.2: Timing and coordination of physiological events are regulated by multiple mechanisms.
b. In animals, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues.
Release and reaction to pheromones: Many animals use pheromones to communicate. They are common among mammals and insects, often related to reproductive behavior. They are the basis of chemical communication. Pheromones also function in nonreproductive behavior. They can be very efficient at remarkable low concentrations
Essential knowledge 2.E.3: Timing and coordination of behavior are regulated by various mechanisms and are important in natural selection.
a. Individuals can act on information and communicate it to others.
1. Innate behaviors are behaviors that are inherited.
Nearly all individuals in a population exhibit virtually the same behavior, despite the internal and environmental differences during development and throughout life.
2. Learning occurs through interactions with the environment and other organisms.
Learning is one of the most powerful ways the environmental conditions can influence behavior. It is based on specific experiences from other organisms
b. In animals, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues.
Release and reaction to pheromones: Many animals use pheromones to communicate. They are common among mammals and insects, often related to reproductive behavior. They are the basis of chemical communication. Pheromones also function in nonreproductive behavior. They can be very efficient at remarkable low concentrations
Essential knowledge 2.E.3: Timing and coordination of behavior are regulated by various mechanisms and are important in natural selection.
a. Individuals can act on information and communicate it to others.
1. Innate behaviors are behaviors that are inherited.
Nearly all individuals in a population exhibit virtually the same behavior, despite the internal and environmental differences during development and throughout life.
2. Learning occurs through interactions with the environment and other organisms.
Learning is one of the most powerful ways the environmental conditions can influence behavior. It is based on specific experiences from other organisms
Behavior
Essential knowledge 2.A.3: Organisms must exchange matter with the environment to grow, reproduce and maintain organization.
3. Living systems depend on properties of water that result fromits polarity and hydrogen bonding.
To foster student understanding of this concept, instructors can
choose an illustrative example such as:
• Cohesion
• Adhesion
• High specific heat capacity
• Universal solvent supports reactions
• Heat of vaporization
• Heat of fusion
• Water’s thermal conductivity
Macromolecules
http://www.tusculum.edu/faculty/home/ivanlare/html/notes/05macromolecules.html
1. Carbon moves from the environment to organisms where it is used to build carbohydrates, proteins, lipids or nucleic acids. Carbon is used in storage compounds and cell formation in all organisms.
2. Nitrogen moves from the environment to organisms where it is used in building proteins and nucleic acids. Phosphorus moves from the environment to organisms where it is used in nucleic acids and certain lipids.
2. Nitrogen moves from the environment to organisms where it is used in building proteins and nucleic acids. Phosphorus moves from the environment to organisms where it is used in nucleic acids and certain lipids.
Structure and function:
Phospholipid layer:
Enduring understanding 2.B: Growth, reproduction
and dynamic homeostasis require that cells create and
maintain internal environments that are different from
their external environments.
Cell membranes separate the internal environment of the cell from the
external environment. The specialized structure of the membrane described
in the fluid mosaic model allows the cell to be selectively permeable, with
dynamic homeostasis maintained by the constant movement of molecules
across the membrane. Passive transport does not require the input of
metabolic energy because spontaneous movement of molecules occurs
from high to low concentrations; examples of passive transport are osmosis,
diffusion, and facilitated diffusion. Active transport requires metabolic energy
and transport proteins to move molecules from low to high concentrations
across a membrane. Active transport establishes concentration gradients
vital for dynamic homeostasis, including sodium/potassium pumps in nerve
impulse conduction and proton gradients in electron transport chains in
photosynthesis and cellular respiration. The processes of endocytosis and
exocytosis move large molecules from the external environment to the internal
environment and vice versa, respectively.
Eukaryotic cells also maintain internal membranes that partition the cell
into specialized regions so that cell processes can operate with optimal
efficiency by increasing beneficial interactions, decreasing conflicting interactions and increasing surface area for chemical reactions to occur.
Each compartment or membrane-bound organelle localizes reactions,
including energy transformation in mitochondria and production of
proteins in rough endoplasmic reticulum.
and dynamic homeostasis require that cells create and
maintain internal environments that are different from
their external environments.
Cell membranes separate the internal environment of the cell from the
external environment. The specialized structure of the membrane described
in the fluid mosaic model allows the cell to be selectively permeable, with
dynamic homeostasis maintained by the constant movement of molecules
across the membrane. Passive transport does not require the input of
metabolic energy because spontaneous movement of molecules occurs
from high to low concentrations; examples of passive transport are osmosis,
diffusion, and facilitated diffusion. Active transport requires metabolic energy
and transport proteins to move molecules from low to high concentrations
across a membrane. Active transport establishes concentration gradients
vital for dynamic homeostasis, including sodium/potassium pumps in nerve
impulse conduction and proton gradients in electron transport chains in
photosynthesis and cellular respiration. The processes of endocytosis and
exocytosis move large molecules from the external environment to the internal
environment and vice versa, respectively.
Eukaryotic cells also maintain internal membranes that partition the cell
into specialized regions so that cell processes can operate with optimal
efficiency by increasing beneficial interactions, decreasing conflicting interactions and increasing surface area for chemical reactions to occur.
Each compartment or membrane-bound organelle localizes reactions,
including energy transformation in mitochondria and production of
proteins in rough endoplasmic reticulum.
Essential knowledge 2.B.1: Cell membranes are selectively permeable due
to their structure.
to their structure.
Cell membranes separate the internal environment of the cell from the external environment.
The head is polar and so is hydrophilic ("water loving"). The tails are non-polar and so are hydrophobic ("water fearing"). Therefore, the heads tend to interact with water and therefore remain in contact with water, and the tails tend to huddle together with one another and exclude water. If enough phospholipids are thrown into water, they will spontaneously form a phospholipid bilayer (that will then ball up to form a sphere): that is the arrangement that minimizes the amount of contact between the hydrophobic tails and the water medium while at the same time maximizes the amount of contact between the hydrophilic heads and water
The head is polar and so is hydrophilic ("water loving"). The tails are non-polar and so are hydrophobic ("water fearing"). Therefore, the heads tend to interact with water and therefore remain in contact with water, and the tails tend to huddle together with one another and exclude water. If enough phospholipids are thrown into water, they will spontaneously form a phospholipid bilayer (that will then ball up to form a sphere): that is the arrangement that minimizes the amount of contact between the hydrophobic tails and the water medium while at the same time maximizes the amount of contact between the hydrophilic heads and water