Amino acids, when strung together in extensive chains, serve as the building blocks of muscles and proteins. At around 37ºC, these amino acid chains allow the body to carry out both macroscopic processes, like moving arms and legs, and microscopic processes, like increasing the rate of chemical reactions. A special class of proteins called enzymes assists in combining reactants to produce products by speeding up the rate of a reaction in one of three ways.

The first way enzymes increase reaction rate is by lowering the activation energy of a reaction. This is done by balancing positively charged amino acids with negatively charged amino acids, creating an electrically neutral environment. This process is called electrostatic interaction. Another way enzymes increase reaction rate is through the use of non-charged amino acids, such as valine and isoleucine, in a process called Van der Waals interactions. In Van der Waals interactions, the non-charged amino acids become temporarily polarized, similar to the permanent polarity of positively and negatively charged amino acids. This interaction brings non-charged amino acids together to stabilize the reactants. The final way enzymes increase reaction rates is by sharing the electrons in its hydrogen atoms with nitrogen, oxygen, or fluorine on the reactant molecules to trap them at the active site. The active site is the part of an enzyme where molecules bind and undergo a chemical reaction.

Enzymes are designed to work in specific parts of the body depending on their functions. For example, an enzyme in the stomach responsible for breaking down food would work most effectively at low pH while an enzyme in the small intestine responsible for absorbing food would work most effectively at high pH. Some enzymes, such as those that function in the blood, work best at intermediate pH. Some enzymes function better at lower temperatures while others require higher temperatures. All enzymes have exponential relationships between their rates of reactions and both pH and temperature, meaning that they function best in narrow pH and temperature windows. Graphs of four enzymes and their rates of reaction at various pH levels and temperature are presented below.

A scientist sets up two experiments using the same reactants. Experiment 1 has no enzymes present and Experiment 2 has 50 mg of enzymes present. Which experiment should create more product after 15 seconds of reaction time?

Amino acids, when strung together in extensive chains, serve as the building blocks of muscles and proteins. At around 37ºC, these amino acid chains allow the body to carry out both macroscopic processes, like moving arms and legs, and microscopic processes, like increasing the rate of chemical reactions. A special class of proteins called enzymes assists in combining reactants to produce products by speeding up the rate of a reaction in one of three ways.

The first way enzymes increase reaction rate is by lowering the activation energy of a reaction. This is done by balancing positively charged amino acids with negatively charged amino acids, creating an electrically neutral environment. This process is called electrostatic interaction. Another way enzymes increase reaction rate is through the use of non-charged amino acids, such as valine and isoleucine, in a process called Van der Waals interactions. In Van der Waals interactions, the non-charged amino acids become temporarily polarized, similar to the permanent polarity of positively and negatively charged amino acids. This interaction brings non-charged amino acids together to stabilize the reactants. The final way enzymes increase reaction rates is by sharing the electrons in its hydrogen atoms with nitrogen, oxygen, or fluorine on the reactant molecules to trap them at the active site. The active site is the part of an enzyme where molecules bind and undergo a chemical reaction.

Enzymes are designed to work in specific parts of the body depending on their functions. For example, an enzyme in the stomach responsible for breaking down food would work most effectively at low pH while an enzyme in the small intestine responsible for absorbing food would work most effectively at high pH. Some enzymes, such as those that function in the blood, work best at intermediate pH. Some enzymes function better at lower temperatures while others require higher temperatures. All enzymes have exponential relationships between their rates of reactions and both pH and temperature, meaning that they function best in narrow pH and temperature windows. Graphs of four enzymes and their rates of reaction at various pH levels and temperature are presented below.

According to the passage, enzymes are made of __________.

Hormones are biochemical messengers utilized by multicellular organisms to coordinate development and behaviors. Hormones are secreted by the endocrine system and are key components in signal cascades that result in various essential activities. Plants, like animals, depend on hormonal signals for physiological adaptation and development.

There are several hormones that are primarily involved with seed germination and sprout formation. Abscisic acid, in high concentrations, prevents seed germination. Auxins are compounds that positively influence cell enlargement, the formation of buds, and the development of roots. Cytokinins influence cell division and shoot formation. Gibberellins promote seed germination as well as flowering and growth post-germination.

Study 1

Several scientists soaked Zea mays (corn) seeds in solutions rich in certain plant hormones. They observed and recorded seed germination and development over a three week period. At the end of the three week period, they measured coleoptile (the protective extension of sprout) and radicle (the primary root) growth of the seeds and plotted them in a graph (Figure 1).

Figure 1

Study 2

Scientists exposed Zea mays (corn) seeds to several hormonal treatments and measured coleoptile growth over a 14-day period and recorded their observations in a line graph (Figure 2). The groups consisted of a control exposed to saline solution, a treatment group exposed to a 0.15 millimolar solution of abscisic acid, and a treatment group exposed to a solution that included 0.15 millimoles of abscisic acid and 0.20 millimoles of gibberellins.

Figure 2

In Study 2, which of the treatments suppressed coleoptile growth over the 14-day period?

Hormones are biochemical messengers utilized by multicellular organisms to coordinate development and behaviors. Hormones are secreted by the endocrine system and are key components in signal cascades that result in various essential activities. Plants, like animals, depend on hormonal signals for physiological adaptation and development.

There are several hormones that are primarily involved with seed germination and sprout formation. Abscisic acid, in high concentrations, prevents seed germination. Auxins are compounds that positively influence cell enlargement, the formation of buds, and the development of roots. Cytokinins influence cell division and shoot formation. Gibberellins promote seed germination as well as flowering and growth post-germination.

Study 1

Several scientists soaked Zea mays (corn) seeds in solutions rich in certain plant hormones. They observed and recorded seed germination and development over a three week period. At the end of the three week period, they measured coleoptile (the protective extension of sprout) and radicle (the primary root) growth of the seeds and plotted them in a graph (Figure 1).

Figure 1

Study 2

Scientists exposed Zea mays (corn) seeds to several hormonal treatments and measured coleoptile growth over a 14-day period and recorded their observations in a line graph (Figure 2). The groups consisted of a control exposed to saline solution, a treatment group exposed to a 0.15 millimolar solution of abscisic acid, and a treatment group exposed to a solution that included 0.15 millimoles of abscisic acid and 0.20 millimoles of gibberellins.

Figure 2

In Study 2, how do gibberellins affect germinating seeds exposed to abscisic acid?

Hormones are biochemical messengers utilized by multicellular organisms to coordinate development and behaviors. Hormones are secreted by the endocrine system and are key components in signal cascades that result in various essential activities. Plants, like animals, depend on hormonal signals for physiological adaptation and development.

There are several hormones that are primarily involved with seed germination and sprout formation. Abscisic acid, in high concentrations, prevents seed germination. Auxins are compounds that positively influence cell enlargement, the formation of buds, and the development of roots. Cytokinins influence cell division and shoot formation. Gibberellins promote seed germination as well as flowering and growth post-germination.

Study 1

Several scientists soaked Zea mays (corn) seeds in solutions rich in certain plant hormones. They observed and recorded seed germination and development over a three week period. At the end of the three week period, they measured coleoptile (the protective extension of sprout) and radicle (the primary root) growth of the seeds and plotted them in a graph (Figure 1).

Figure 1

Study 2

Scientists exposed Zea mays (corn) seeds to several hormonal treatments and measured coleoptile growth over a 14-day period and recorded their observations in a line graph (Figure 2). The groups consisted of a control exposed to saline solution, a treatment group exposed to a 0.15 millimolar solution of abscisic acid, and a treatment group exposed to a solution that included 0.15 millimoles of abscisic acid and 0.20 millimoles of gibberellins.

Figure 2

In Study 2, what was the average length of the coleoptiles in the control trial on the 8th day of the study?

Drosophila melanogaster, the common fruit fly, is frequently utilized for genetic studies due to its simple food requirements, hardy nature, and because it completes its life cycle within 12 days at room temperature. This particular fly species has four pairs of chromosomes with traits that have been studied and observed to be inherited in a Mendelian fashion.

The predictive capacity of Mendelian genetics depends on traits whose physiological characteristics, know as phenotypes, are determined by genetic combinations of alleles, known as genotypes. The exhibition of observable traits is determined by the combination of two alleles for a specific characteristic. For example, the dominant allele for the wild type red eye color is E and the recessive sepia-brown color is e. Likewise, the dominant allele for long wings is W and the recessive allele for short wings is w. When a dominant allele is present with a recessive one, the organism physically exhibits the trait of the dominant allele and the organism is known as heterozygous for that trait. If an organism has two dominant or two recessive alleles for a particular trait, it is known as homozygous for that trait. Only when two recessive alleles are present does the organism physically exhibit the trait of the recessive allele. Heterozygous individuals are often known as carriers because the dominant allele phenotype masks the recessive allele phenotype and the organism can carry the recessive allele without exhibiting any of its physical traits.

Study 1

A researcher wants to study the inheritance of eye color in fruit flies. The scientist mates a homozygous recessive (ee) group with a homozygous dominant (EE) group in order to obtain the F1 Generation. Two members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 1).

Table 1

Study 2

A researcher decided to perform a dihybrid cross of fruit flies possessing red eyes and long wings with fruit flies possessing sepia-brown eyes and short wings. The scientist bred homozygous dominant flies with homozygous recessive flies in the F1 Generation. The members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 2).

Table 2

In Study 2, what was the genotype of the fruit flies in the F1 generation?

Drosophila melanogaster, the common fruit fly, is frequently utilized for genetic studies due to its simple food requirements, hardy nature, and because it completes its life cycle within 12 days at room temperature. This particular fly species has four pairs of chromosomes with traits that have been studied and observed to be inherited in a Mendelian fashion.

The predictive capacity of Mendelian genetics depends on traits whose physiological characteristics, know as phenotypes, are determined by genetic combinations of alleles, known as genotypes. The exhibition of observable traits is determined by the combination of two alleles for a specific characteristic. For example, the dominant allele for the wild type red eye color is E and the recessive sepia-brown color is e. Likewise, the dominant allele for long wings is W and the recessive allele for short wings is w. When a dominant allele is present with a recessive one, the organism physically exhibits the trait of the dominant allele and the organism is known as heterozygous for that trait. If an organism has two dominant or two recessive alleles for a particular trait, it is known as homozygous for that trait. Only when two recessive alleles are present does the organism physically exhibit the trait of the recessive allele. Heterozygous individuals are often known as carriers because the dominant allele phenotype masks the recessive allele phenotype and the organism can carry the recessive allele without exhibiting any of its physical traits.

Study 1

A researcher wants to study the inheritance of eye color in fruit flies. The scientist mates a homozygous recessive (ee) group with a homozygous dominant (EE) group in order to obtain the F1 Generation. Two members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 1).

Table 1

Study 2

A researcher decided to perform a dihybrid cross of fruit flies possessing red eyes and long wings with fruit flies possessing sepia-brown eyes and short wings. The scientist bred homozygous dominant flies with homozygous recessive flies in the F1 Generation. The members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 2).

Table 2

In Study 2, what physical characteristics were exhibited by the fruit flies in the F1 Generation?

Drosophila melanogaster, the common fruit fly, is frequently utilized for genetic studies due to its simple food requirements, hardy nature, and because it completes its life cycle within 12 days at room temperature. This particular fly species has four pairs of chromosomes with traits that have been studied and observed to be inherited in a Mendelian fashion.

The predictive capacity of Mendelian genetics depends on traits whose physiological characteristics, know as phenotypes, are determined by genetic combinations of alleles, known as genotypes. The exhibition of observable traits is determined by the combination of two alleles for a specific characteristic. For example, the dominant allele for the wild type red eye color is E and the recessive sepia-brown color is e. Likewise, the dominant allele for long wings is W and the recessive allele for short wings is w. When a dominant allele is present with a recessive one, the organism physically exhibits the trait of the dominant allele and the organism is known as heterozygous for that trait. If an organism has two dominant or two recessive alleles for a particular trait, it is known as homozygous for that trait. Only when two recessive alleles are present does the organism physically exhibit the trait of the recessive allele. Heterozygous individuals are often known as carriers because the dominant allele phenotype masks the recessive allele phenotype and the organism can carry the recessive allele without exhibiting any of its physical traits.

Study 1

A researcher wants to study the inheritance of eye color in fruit flies. The scientist mates a homozygous recessive (ee) group with a homozygous dominant (EE) group in order to obtain the F1 Generation. Two members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 1).

Table 1

Study 2

A researcher decided to perform a dihybrid cross of fruit flies possessing red eyes and long wings with fruit flies possessing sepia-brown eyes and short wings. The scientist bred homozygous dominant flies with homozygous recessive flies in the F1 Generation. The members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 2).

Table 2

In Study 2, what proportion of the fruit flies in the F2 Generation are homozygous recessive for both traits?

Drosophila melanogaster, the common fruit fly, is frequently utilized for genetic studies due to its simple food requirements, hardy nature, and because it completes its life cycle within 12 days at room temperature. This particular fly species has four pairs of chromosomes with traits that have been studied and observed to be inherited in a Mendelian fashion.

The predictive capacity of Mendelian genetics depends on traits whose physiological characteristics, know as phenotypes, are determined by genetic combinations of alleles, known as genotypes. The exhibition of observable traits is determined by the combination of two alleles for a specific characteristic. For example, the dominant allele for the wild type red eye color is E and the recessive sepia-brown color is e. Likewise, the dominant allele for long wings is W and the recessive allele for short wings is w. When a dominant allele is present with a recessive one, the organism physically exhibits the trait of the dominant allele and the organism is known as heterozygous for that trait. If an organism has two dominant or two recessive alleles for a particular trait, it is known as homozygous for that trait. Only when two recessive alleles are present does the organism physically exhibit the trait of the recessive allele. Heterozygous individuals are often known as carriers because the dominant allele phenotype masks the recessive allele phenotype and the organism can carry the recessive allele without exhibiting any of its physical traits.

Study 1

A researcher wants to study the inheritance of eye color in fruit flies. The scientist mates a homozygous recessive (ee) group with a homozygous dominant (EE) group in order to obtain the F1 Generation. Two members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 1).

Table 1

Study 2

A researcher decided to perform a dihybrid cross of fruit flies possessing red eyes and long wings with fruit flies possessing sepia-brown eyes and short wings. The scientist bred homozygous dominant flies with homozygous recessive flies in the F1 Generation. The members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 2).

Table 2

Drosophila melanogaster, the common fruit fly, is frequently utilized for genetic studies due to its simple food requirements, hardy nature, and because it completes its life cycle within 12 days at room temperature. This particular fly species has four pairs of chromosomes with traits that have been studied and observed to be inherited in a Mendelian fashion.

The predictive capacity of Mendelian genetics depends on traits whose physiological characteristics, know as phenotypes, are determined by genetic combinations of alleles, known as genotypes. The exhibition of observable traits is determined by the combination of two alleles for a specific characteristic. For example, the dominant allele for the wild type red eye color is E and the recessive sepia-brown color is e. Likewise, the dominant allele for long wings is W and the recessive allele for short wings is w. When a dominant allele is present with a recessive one, the organism physically exhibits the trait of the dominant allele and the organism is known as heterozygous for that trait. If an organism has two dominant or two recessive alleles for a particular trait, it is known as homozygous for that trait. Only when two recessive alleles are present does the organism physically exhibit the trait of the recessive allele. Heterozygous individuals are often known as carriers because the dominant allele phenotype masks the recessive allele phenotype and the organism can carry the recessive allele without exhibiting any of its physical traits.

Study 1

A researcher wants to study the inheritance of eye color in fruit flies. The scientist mates a homozygous recessive (ee) group with a homozygous dominant (EE) group in order to obtain the F1 Generation. Two members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 1).

Table 1

Study 2

A researcher decided to perform a dihybrid cross of fruit flies possessing red eyes and long wings with fruit flies possessing sepia-brown eyes and short wings. The scientist bred homozygous dominant flies with homozygous recessive flies in the F1 Generation. The members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 2).

Table 2

In Study 2, how many physical outcomes are possible for the fruit flies in the F2 Generation?