Flashcards: Human Biology Exam 1 — 39 cards

What forms molecules in the body's structural hierarchy?

Atoms form molecules.

What is the highest level in the body's structural hierarchy?

The organism is the highest level.

Which characteristic of life involves maintaining stable internal conditions?

Homeostasis involves maintaining stable internal conditions.

What is homeostasis?

Homeostasis is maintaining a stable internal environment through dynamic equilibrium.

What are the three components of a feedback loop?

A receptor, a control center, and an effector.

How does negative feedback affect an initial change?

It opposes the initial change to maintain homeostasis.

How does positive feedback affect an initial change?

It reinforces the initial change.

What does the atomic number represent in an atom?

The number of protons in the atom's nucleus.

How do isotopes differ from ions?

Isotopes differ in neutron number; ions differ in electron number and charge.

What is a chemical bond?

An attraction holding atoms together through various interactions.

How do hydrophilic substances interact with water?

They interact readily with water.

How do hydrophobic substances interact with water?

They do not interact readily with water.

Which factors affect the rate of a chemical reaction?

Concentration, catalysts, and temperature affect reaction rate.

What is oxidation associated with in redox reactions?

Exergonic reactions.

What is reduction associated with in redox reactions?

Endergonic reactions.

What distinguishes carbohydrates from lipids in organic compounds?

Carbohydrates have characteristic properties and examples, while lipids include saturated and unsaturated forms.

How do amino acids form proteins?

Amino acids join through peptide bonds to form proteins.

What structural levels can proteins have?

Proteins can have primary, secondary, tertiary, and quaternary structures.

What is protein denaturation?

Protein denaturation is the alteration of a protein's structure impairing its function.

Name one function of proteins.

Proteins function in catalysis.

What are the three steps of an enzymatic reaction?

Substrate binding, reaction occurrence, and product release.

What are ATP and cAMP classified as?

ATP and cAMP are nucleotides.

What roles do DNA and RNA play?

DNA and RNA are nucleic acids involved in genetic information and protein synthesis.

What is the plasma membrane composed of?

Lipids and proteins.

What roles do membrane proteins perform?

They act as enzymes, channels, receptors, second-messenger components, identity markers, and carriers.

What distinguishes diffusion from active transport?

Diffusion moves substances down a gradient without energy, active transport uses energy.

What does phagocytosis involve in vesicular transport?

Taking in particles.

What does pinocytosis involve in vesicular transport?

Taking in fluid.

Name three cell surface extensions.

Cilia, flagella, and microvilli.

Which organelles are included in cells?

Lysosomes, Golgi complex, ribosomes, peroxisomes, and mitochondria.

Besides organelles, what else is found within cells?

Inclusions.

What three components make up a DNA nucleotide?

Phosphate, deoxyribose, and a nitrogenous base.

Which nitrogenous bases pair together in DNA?

Adenine pairs with thymine and guanine pairs with cytosine.

What is the difference between a gene and a genome?

A gene is a segment of genetic information; the genome is the complete genetic material.

What are the two main steps in protein synthesis?

Transcription and translation.

In the example, which mRNA codon corresponds to the DNA triplet CCT?

GGA.

Which amino acid is specified by the mRNA codon GGA?

Glycine.

What are the stages of translation?

Initiation, elongation, termination, and packaging or export.

With which processes is mitosis associated?

DNA replication and cellular division.