Related Concept Videos

Non-equilibrium in the Cell 01:16

4.3K

An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system...

Communication 01:03

7.7K

Communication between two animals occurs when one animal transmits an information signal that causes a change in the animal that receives the information. Organisms communicate with one another in a host of different ways. Signals can be auditory, chemical, visual, tactile, or a combination of these. Communication is a critical behavioral adaptation that promotes survival, growth, and reproduction.

Types of Communication

A common form of communication is visual. Visual communication can be...

Genetic Lingo 01:11

102.2K

Overview

An organism is diploid if it inherits two variants, or alleles, of each gene, one from each parent. These two alleles constitute the genotype for a given gene. The term genotype is also used to refer to an organism’s complete set of genes. A diploid organism with two identical alleles has a homozygous genotype, whereas two different alleles indicates a heterozygous genotype. Observable traits arising from genotypes are called phenotypes, which can also be influenced by...

Hearing 01:31

52.0K

When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness.

Sound waves are collected by the external ear and amplified as they travel through the ear canal. When sounds reach the junction between the outer and middle ear, they vibrate the tympanic membrane—the eardrum. The resulting mechanical energy causes the...

What is Genetic Engineering? 00:49

73.9K

Overview

Genetic engineering is the process of modifying an organism’s DNA to introduce new, desirable traits. Many organisms, from bacteria to plants and animals, have been genetically modified for academic, medical, agricultural, and industrial purposes. While genetic engineering has definite benefits, ethical concerns surround modifying humans and our food supply.

Scientists can Deliberately Modify an Organism’s Genome

Genetic engineering is possible because the genetic...

The Synapse 02:47

124.6K

Neurons communicate with one another by passing on their electrical signals to other neurons. A synapse is the location where two neurons meet to exchange signals. At the synapse, the neuron that sends the signal is called the presynaptic cell, while the neuron that receives the message is called the postsynaptic cell. Note that most neurons can be both presynaptic and postsynaptic, as they both transmit and receive information.

An electrical synapse is one type of synapse in which the pre-...