Notes, summaries, assignments, exams, and exercises for Biology for University

Drug Tolerance and Dependence

1. In the stage of tolerance to the drug involved, the following are present in the nucleus: cAMP, protein CREB, dynorphin, and specific genes.
2. For the fight-or-flight response, both predominantly sympathetic activity and inhibited digestion occur.
3. Synaptic efficiency is incorrect; it increases the activity of presynaptic transporters.

Motor Control and Spinal Cord Injuries

4. If a rat makes a hemisection of the reticulospinal tract from the motor cortex (right side) at the bridge, the rat may not move the muscles on the left side of its body.
5. If you would like to block the action of cocaine in reward circuitry, you should inhibit dopamine receptors in the nucleus accumbens.

Alzheimer's Disease

6. In an old man with advanced Alzheimer'

Classification of Spanish Sounds

The production of speech sounds begins as air travels from the trachea to the lungs. The vibration of the vocal cords determines the voicing of a sound:

• Voiced: Vocal cords vibrate.
• Voiceless (Deaf): Vocal cords do not vibrate.

The position of the uvula determines the resonance:

• Oral: Uvula is raised, blocking the nasal cavity; air exits through the mouth.
• Nasal: Uvula is relaxed; air exits through both the mouth and nose.

When air reaches the mouth, it is classified based on obstacles created by the tongue and lips as either a consonant or a vowel.

Modes of Articulation in the Oral Tract

• Occlusive (Plosive): Complete closure of articulators followed by an abrupt release of air (e.g., /p/, /t/, /k/, /b/, /d/, /g/).
• Approximant:

Proteins and Gene Expression

• Activator: A DNA-binding protein that positively regulates the expression of one or more genes, i.e., the rate of transcription increases when an activator is bound to DNA. It is a positive modulator.
• Aminoacyl-tRNA Synthetase: Allosteric enzymes that catalyze the synthesis of aminoacyl-tRNA at the expense of ATP energy.
• Attenuation/Attenuator: An RNA sequence involved in the regulation of the expression of certain genes. The terminator functions in transcription.
• Inductor: A signal molecule that, when coupled with a regulatory protein, produces an increase in the expression of a particular gene.
• Leucine Zipper: A structural protein motif involved in protein-protein interactions in many eukaryotic regulatory proteins.

The nervous system is the body's communication network, a complex system of nerves and cells (neurons) that carry signals to and from the brain and spinal cord to different parts of the body. It is divided into two main parts: the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

Neuron Structure and Types

Neurons are the fundamental building blocks of the nervous system. They are specialized cells that transmit electrical and chemical signals. While they can vary in size and shape, most neurons share a basic structure:

• Cell Body (Soma): The central part of the neuron, containing the nucleus and other organelles necessary for the cell's function.
• Dendrites: Branch-like extensions that receive incoming signals from other neurons.

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...

Core Principles of Photosynthesis

The Light-Dependent Reactions

1. When oxygen is released during photosynthesis, what is it a direct by-product of?

   It is a direct by-product of splitting water molecules.

2. What is the role of pigment molecules in a light-harvesting complex?

   Within the thylakoid membranes, they absorb and transfer light energy to the reaction-center chlorophyll.

3. What is directly associated with photosystem I?

   It is directly associated with receiving electrons from the thylakoid membrane's electron transport chain.

4. How can one detect the lack of photosystem II in certain photosynthetic organisms?

   The most effective method is to test for the liberation of O2 in the presence of light, as photosystem II is responsible for splitting water to

NO BANK/FIB-MULTI Panceras

Endocrine Functions § Pancreatic islets § Secrete hormones insulin and glucagon into blood Exocrine functions § Secretes pancreatic juice into duodenum § Alkaline fluid introduced with enzymes neutralizes chyme from stomach Pancreatic Juice

• Water, bicarbonate solution, enzymes
• Bicarbonate solution: neutralizes gastric HCL & shift pH of duodenum to 8
• Enzymes: § Pancreatic amylase: digests salts § Trypsinogen - digests proteins § Lipase - digests triglycerides

Agriculture:

Deliberate land modification through plant cultivation and raising animals for food or profit Dominant economic activity Requires physical and demographic contributions in regions

Hemoglobin:

Globin combined with 4 iron atoms • 280 million molecules...

Adaptation to Parasitism

Normally, endoparasites are animals that have undergone major structural changes regarding their architectural pattern, such as the disappearance of unnecessary structures. Locking mechanisms are another common characteristic in parasitic animals. Reproduction and life cycle are significantly affected in animal parasites. Populations often maintain very low levels, so finding a partner can be a problem. The appearance of hermaphroditism ensures reproduction despite the cost of producing two reproductive systems. The production of a high number of eggs compensates for the low probability of one completing the life cycle. The cyst is one of the more developed structures in these animals. Finally, to complete the life cycle,...

Glycolysis: Preparatory Phase (Cytosol)

Glycolysis involves the breakdown of glucose in the cytosol.

1. Glucose + ATP → ADP + Glucose 6-phosphate (G6P) + Pi (Enzyme: Hexokinase) (Irreversible)
2. Glucose 6-phosphate ↔ Fructose 6-phosphate (F6P) (Enzyme: Phosphoglucose Isomerase) (Reversible)
3. Fructose 6-phosphate + ATP → Fructose 1,6-bisphosphate (F1,6BP) + ADP + Pi (Enzyme: Phosphofructokinase) (Irreversible)
4. Fructose 1,6-bisphosphate ↔ Glyceraldehyde 3-phosphate (G3P) + Dihydroxyacetone Phosphate (DHAP) (Enzyme: Aldolase) (Reversible)
5. Dihydroxyacetone Phosphate ↔ Glyceraldehyde 3-phosphate (G3P) (Enzyme: Triose Phosphate Isomerase) (Reversible)

Glycolysis: Payoff Phase

Oxidation of Glyceraldehyde 3-phosphate and subsequent steps leading to pyruvate,...