Notes, summaries, assignments, exams, and problems for Biology

Microbial Secretion Systems

Matching

Which secretion system:

• Moves protein from the periplasmic space to the exterior? 2, 4, 5
• Moves DNA from one cell to another through conjugation? 4
• Moves protein from cytoplasm to exterior (not into another cell)? 1, 3
• Relies on Sec to do the first step of transportation? 2, 4, 5
• Requires ATP? All
• A domain of the protein itself forms a beta-barrel that inserts into the outer membrane (i.e., forming a pore), allowing the rest of the protein to pass through? 5
• The protein being transported carries a C-terminal signal peptide? 1
• The preprotein (before final folding) being transported carries an N-terminal signal peptide? Sec

Viral Multiplication

Six Steps to Viral Multiplication:

1. Attachment to host cell
2. Entry
3. Uncoating of

Plant Nutrition Fundamentals

Photosynthesis Definition

Photosynthesis is the process by which plants manufacture carbohydrates from raw materials using energy from light.

Photosynthesis Word Equation

The word equation for photosynthesis is: carbon dioxide + water → (in the presence of light and chlorophyll) → glucose + oxygen.

Photosynthesis Balanced Equation

The balanced chemical equation for photosynthesis states that the combination of carbon dioxide, water, and light energy produces a carbohydrate (glucose) and oxygen.

The chemical formula is: 6CO₂ + 6H₂O + Light Energy → C₆H₁₂O₆ + 6O₂.

Chlorophyll's Role in Energy Transfer

Chlorophyll transfers light energy into chemical energy stored in molecules, enabling the synthesis of... Continue reading "Plant Nutrition and Photosynthesis Essentials" »

Cellular Respiration

1. Definition and Chemical Equation

Cellular respiration is the chemical reaction in which glucose and oxygen are converted into water, carbon dioxide, and energy (ATP). The balanced chemical equation for cellular respiration is: C₆H₁₂O₆ + 6 O₂ --> 6 CO₂ + 6 H₂O + ATP

2. Location of Respiration

Cellular respiration takes place in the mitochondria of living cells.

3. Phases of Respiration and ATP Production

Cellular respiration occurs in three stages: glycolysis, the Krebs cycle, and electron transport. Glycolysis takes place in the cytoplasm and results in a net gain of two ATP molecules.

4. ATP and Energy Production

ATP provides energy to the cell when it is broken down into ADP (adenosine diphosphate) and inorganic phosphate,... Continue reading "Cellular Respiration and Cell Cycle: Key Concepts and Processes" »

Vertebrate animals belong to the Animal Kingdom and have the following characteristics:

• They have an internal skeleton that allows movement, protects the organs, and gives support to their body.
• They have blood to carry the nutrients and waste products throughout the body.
• They have articulated limbs (fins, wings, or legs).

We are going to study the vertebrates' groups:

1. Fish

• Aquatic (they have a fusiform body, thinner in the tips, and fins). They breathe through gills.
• Poikilothermic (they cannot maintain constant body temperature).
• They have a lateral line (a line that crosses their body that is able to detect vibrations in the water).
• They have external fertilization: gametes join in the environment, outside of the female's body.
• They can be oviparous

Ecosystem

An ecosystem is a community of plants and animals (living things) that interact with each other and their natural surroundings, including non-living things such as rocks, water, and air. Each ecosystem is sustained by a flow of energy through it and the recycling of nutrients within it.

Community

When plants and animals live together, they form a community.

Photosynthesis

Photosynthesis is the process in which plants absorb CO₂ from the air and convert it into sugar using the sun's energy.

Biomes

Biomes are large ecosystems at the global scale where the climate and vegetation are uniform.

Xerophytic Plants

Xerophytes are plants that have adapted by altering their physical structure to survive in harsh climates. These plants exhibit several... Continue reading "Introduction to Ecosystems and Ecology" »

The Interaction Function

The interaction function enables people to perceive changes and stimuli that occur both inside their bodies and their environment, to interpret or process them and generate coordinated responses in order to survive.

1.1 Perceiving Stimuli

The interaction function can be divided into 3 stages: perception of stimuli, processing of the information and generation of responses.

A stimulus is a physical or chemical change that takes place outside or inside the body and triggers a response in it.

Our bodies contain specialist cells, called receptors, which perceive stimuli and send the information they detect to the coordination centres.

Types of Receptors

• Internal receptors perceive changes inside the body, such as a rise in blood

Muscle spindles stimulate stretch, while Golgi tendon organs stimulate muscle contraction. Cerebellar tremor is characterized by low frequency. Motor pathways begin in the cerebral cortex and brainstem. Lower spinal cord motoneurons innervate skeletal muscles, including extrafusal and intrafusal fibers. Stimulation of muscle spindles or Golgi tendon organs is accomplished through the reticulospinal tract.

Muscle Tone and Movement Disorders

• Hypotonia: Decreased muscle tone
• Dyskinesia: Atypical, unconscious muscle movement
• Hypertonia: Increased muscle tone
• Spasticity: Hyper-contraction of muscles
• Akinesia: Atypical unconscious posture

Cortical Control of Movement

Layer V contains pyramidal neurons. The primary motor cortex contains smaller and fewer... Continue reading "Motor Control: Pathways, Neurons, and Muscle Function" »

Replication

AAGGCCTAGC-TTCCGGATCG

Transcription

AAGGCCTAGC

Translation

How to Read the RNAm to Make Proteins After the Transcribing DNA as RNAm

It exists from the nucleus to the cytoplasm. There, ribosomes are waiting for the RNAm, and the two subunits look for the first codon AUG. The RNAm is read by triplets. All the possible combinations of codons and its corresponding amino acids are called genetic code. Mutation is the alteration of the DNA sequence that can be transmitted to the offspring (if it occurs in gametes).

Addition:

A nucleotide is added

Deletion:

A nucleotide is removed

Substitution:

A nucleotide is changed

1. Fungi obtain nutrients through absorption.
2. The body of most fungi consists of threadlike hyphae, which form a network called a mycelium.
3. Some fungal species live in plants and can kill herbivores that feed on the plant. What type of relationship does this fungus have with its host? Mutualistic
4. What sexual processes in fungi generate genetic variation? Karyogamy and meiosis
5. Almost all of the members of this phylum form arbuscular mycorrhizae in a mutualistic partnership with plants. Glomeromycota
6. From the human perspective, which of the following kinds of fungi would be considered the least useful or beneficial? Rusts
7. Which of the following best describes the physical relationship of the partners involved in lichens? Photosynthetic cells are