Biology Chapter: Metabolism and Photosynthesis

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Questions and Answers

What is the primary product of glycolysis?

Lactic acid (correct)

Oxygen

Glucose

Carbon dioxide

Which process utilizes energy from the sun to synthesize glucose?

Glycolysis

Oxidative metabolism

Photosynthesis (correct)

Fermentation

How does oxidative metabolism compare to glycolysis in energy production?

Is an entirely anaerobic process

Produces the same energy as glycolysis

Releases much more energy than glycolysis (correct)

Produces less energy than glycolysis

What major atmosphere change was influenced by the development of photosynthesis?

Increase in oxygen levels Signup and view all the answers

What component is essential for oxidative metabolism to occur?

Oxygen Signup and view all the answers

What was a major outcome of Stanley Miller's experiment in 1953?

The spontaneous formation of several organic molecules. Signup and view all the answers

Which organic molecules were identified as products of Stanley Miller's experiment?

Amino acids such as alanine and aspartic acid. Signup and view all the answers

Which macromolecule is stated to be capable of self-replication?

Nucleic acids. Signup and view all the answers

What characteristic did the first macromolecule that gave rise to life need to possess?

It should be able to replicate itself. Signup and view all the answers

What do complementary nucleotide pairs in RNA facilitate?

The replication of RNA strands. Signup and view all the answers

Which part of the phospholipid molecule is hydrophobic?

The long hydrophobic tails. Signup and view all the answers

How did the first cell likely arise, according to the information provided?

From self-replicating RNA coated in phospholipid membranes. Signup and view all the answers

What is the significance of the central dogma in molecular biology?

It describes the flow of genetic information. Signup and view all the answers

What significant feature of C. elegans makes it suitable for genetic studies?

Its hermaphroditic breeding system Signup and view all the answers

Which Nobel Prize-winning work is associated with C. elegans?

Research on apoptosis Signup and view all the answers

What is the primary biological process that RNA interference (RNAi) was first described to regulate?

Gene silencing Signup and view all the answers

Which characteristic of C. elegans allows for in vivo monitoring of biological processes?

Its transparent body Signup and view all the answers

What is a unique characteristic of zebrafish compared to mammals?

Zebrafish have the ability to regenerate certain tissues. Signup and view all the answers

What is a key feature of the life cycle of Drosophila melanogaster?

Complete metamorphosis Signup and view all the answers

How fast can Drosophila melanogaster females start laying eggs after emerging?

After one day Signup and view all the answers

How much of the zebrafish genome is estimated to be complete?

85-90% Signup and view all the answers

What environmental condition is crucial for Drosophila melanogaster's reproduction?

Presence of yeast Signup and view all the answers

What percentage of genes do zebrafish share with humans?

80% Signup and view all the answers

What developmental stage follows the larval stages in the life cycle of Drosophila melanogaster?

Pupal stage Signup and view all the answers

What is the gestation period for female domestic mice?

20 days Signup and view all the answers

Why are mice often referred to as 'pocket human beings'?

They share a variety of genetic diseases with humans. Signup and view all the answers

Where is the genomic information of zebrafish primarily stored?

Zebra Fish Information Network (ZFIN) Signup and view all the answers

What is the typical average number of offspring per female domestic mouse?

7 Signup and view all the answers

Which of the following is a common research application of using zebrafish?

Investigating regenerative processes Signup and view all the answers

What is the primary reason Caenorhabditis elegans is used as a model organism in research?

Its transparency allows for easy study of developmental processes. Signup and view all the answers

How many somatic cells does a typical Caenorhabditis elegans organism have?

959 Signup and view all the answers

What does the hermaphroditic form of Caenorhabditis elegans possess?

Both male and female sexual organs. Signup and view all the answers

Which of the following statements correctly describes the genome of Caenorhabditis elegans?

It was the first multicellular organism to have its genome sequenced. Signup and view all the answers

What is the estimated lifespan of an adult Caenorhabditis elegans?

2-3 weeks Signup and view all the answers

What percentage of genes in Caenorhabditis elegans are estimated to have human homologues?

36% Signup and view all the answers

Which of the following best describes the digestive system of Caenorhabditis elegans?

It includes a stoma, pharynx, and intestine. Signup and view all the answers

What role does self-fertilization play in hermaphroditic Caenorhabditis elegans?

It allows for reproduction in the absence of males. Signup and view all the answers

What property of fluorescent substances is utilized in fluorescence microscopy?

They absorb and emit light at different wavelengths. Signup and view all the answers

Which component can be selectively stained using fluorescent dyes?

Specific nucleic acids and cellular components. Signup and view all the answers

What is the function of the dichroic mirror in fluorescence microscopy?

To deflect emitted light towards the detector. Signup and view all the answers

What advantage does GFP provide in fluorescence microscopy?

It can be fused to any protein of interest for studying. Signup and view all the answers

What was the significance of using MitoTracker Red CMXRos in the study mentioned?

It vividly labels the intracellular mitochondrial network. Signup and view all the answers

Which statement best describes the fluorescent dye acridine orange?

It selects a specific structure, primarily the nucleus. Signup and view all the answers

What microscopy method would best show the intracellular distribution of molecules in living cells?

Fluorescence microscopy. Signup and view all the answers

What is the role of hybridization in fluorescence microscopy as mentioned in the content?

To detect specific genes or RNA transcripts. Signup and view all the answers

Study Notes

Unit 1: Overview of the cell and cell research

Biology is the study of the composition, development, functioning, links and distribution of living things.
Cells are the fundamental unit of living beings, capable of independent reproduction.
Cell biology is a discipline specializing in cell analysis, focusing on structure, function, components, interactions, and properties of microscopic units. It draws on information from genetics, biochemistry, immunology, and other areas of knowledge.
Molecular biology studies the processes of living beings from a molecular point of view, focusing on macromolecules like nucleic acids and proteins. It seeks to explain life's phenomena through their macromolecular properties.
Cell biology studies cells, while molecular biology focuses on the molecules within cells.

Index

Origin and evolution of cells
Cells as experimental models
Cell biology instruments

1.1 Origin and evolution of cells

The cell is the basic structural, functional, and biological unit of all known organisms.
It's an independently acting unit.
Different cell types exist
Multicellular organism development

1.2 Cells as experimental models

Unicellular models: Escherichia coli, Yeast
Multicellular models: Arabidopsis thaliana, Caenorhabditis elegans, Drosophila melanogaster, Danio rerio, Mus musculus

Model organisms

All cells descended from a common ancestor, with fundamental properties conserved throughout evolution.
Understanding one organism's cells helps understand other organisms, including humans. Some organisms are more easily studied in labs for various reasons.

Escherichia coli

A rod-shaped bacterium, usually found in the intestines of vertebrates.
Its simplicity and easy cultivation in the lab make it useful for genetic studies, genetic manipulation, and understanding fundamental life mechanisms.
Its genome is a circular double-stranded DNA molecule, roughly 4.6 million base pairs long.

Yeast

Simple eukaryotes that divide every 2 hours and form colonies from single cells.
Used in various genetic manipulations to analyze fundamental eukaryotic processes like DNA replication and transcription.
Two main types for this are Saccharomyces cerevisiae and Schizosaccharomyces pombe, differing in their division methods.
- 2 different division types: Budding, and fission

Saccharomyces cerevisiae

First eukaryotic organism sequenced (around 1996)
Has a relatively small genome (12 million base pairs) containing about 6000 genes.
16 linear chromosomes. Contains mitochondria, no chloroplasts.
An important model to study many molecular processes.

Drosophila melanogaster (fruit fly)

Found practically worldwide, feeding on yeast and other organic materials.
A complete metamorphosis with four stages.
Used to study genetic traits and their roles in development, as well as studying diseases.
Its short life cycle (10-15 days) and ease of reproduction in large numbers make it suitable for genetic studies.

Arabidopsis thaliana

A small weed of the mustard family.
Ideal model for plant molecular biology research, with thousands of shoots per plant within 8-10 weeks.
Used for studies of germination, flowering, and responses to different stresses.

Danio rerio (zebrafish)

A small, active fish common in aquariums.
Its natural habitat includes calm waters, such as those around the Ganges Region in India.
Known for its transparency and rapid embryonic development and easy maintenance.
Used in studies of development, genetics, neural processes, drug discovery, and regeneration.

Mus musculus (mouse)

A small rodent inhabiting urban environments and forests.
Small size (typically 35 grams or less) and short gestation period (usually 20 days) with several offspring, make it a suitable lab animal.
Widely used in research to study several areas such as neuroscience, pharmacology, and physiology.
Genome sequenced in 2002, with a high percentage of shared genes with humans for genetic study..

Cell Biology Instruments (a)

Optical Microscopy: Magnification to about 1000 times.
Electron Microscopy: High-resolution views of structures.
Super-Resolution Microscopy: Enables high-resolution images of cellular structures.

Cell Biology Instruments (b)

Specimen preparation
Flow cytometry
Subcellular separation
Growth of animal cells in culture
Virus

Immunohistochemical techniques

A technique used to detect the presence of a specified protein within a tissue section using specific antibodies.
Immunohistochemistry is crucial in pathology for disease diagnosis, identifying viral proteins and monitoring oncogene overexpression.
- Direct technique: uses a primary antibody that is conjugated to a detectable substance.
- Indirect technique: uses a secondary antibody that recognizes the primary one.

Flow Cytometry

A technique for analyzing the number, size, and complexity of cells in a suspension.
Measures forward and side scatter measurements to determine cell size and internal complexity respectively.

Subcellular separation

Methods to separate organelles from other cell components include physical (osmotic shock, ultrasound, mechanical grinding) and enzymatic (lysozyme) methods.

Differential Centrifugation

A technique used to separate cellular components/organelles based on differences in size and density..
The process often involves several centrifugation steps with progressively higher speeds.

Density Gradient Centrifugation

Technique to isolate organelles (or other macromolecules) by sedimentation on a density gradient.
The higher the density of the separation substance, the higher degree of purification.

Cell cultures

A process for growing cells in a controlled environment, typically in the laboratory.
Primary cultures: Initially obtaining cells from a tissue sample
Secondary cultures: Subsequent cultures derived from primary cultures, usually maintained in the laboratory.

Immortal cells

Tumor-derived cells that can proliferate indefinitely in culture.
A notable example is HeLa cells (1951) obtained from a tumor.

Necessary culture medium

Culture media: A liquid medium containing salts, glucose, amino acids, vitamins and a serum source, and other growth factors.

Viruses

Viruses require a host cell to replicate and grow.
The host cell provides a system to study cell function.
Studies using viruses have revealed fundamental aspects of molecular genetics, RNA potential, and oncogene discovery.

Additional information

Links to external YouTube videos providing detailed examples of steps and processes.

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Description

Test your knowledge on key metabolic processes including glycolysis, oxidative metabolism, and photosynthesis. This quiz covers the basics of how energy is produced and utilized in living organisms, along with the significant atmospheric impact of photosynthesis. Ideal for students studying biology at various levels.