Biology Chapter 1: Discovery of Cells

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Questions and Answers

What process do cells undergo to reproduce?

Fission

Division (correct)

Meiosis

Budding

Which molecule stores energy in cells derived from glucose?

NADPH

DNA

RNA

ATP (correct)

What factor is essential for increasing the rate of chemical reactions in cells?

Enzymes (correct)

Proteins

Buffer solutions

Acids

How do cells primarily acquire energy?

Photosynthesis Signup and view all the answers

What is the total of all chemical reactions that take place in a cell called?

Metabolism Signup and view all the answers

Which type of proteins change shape to initiate mechanical activities within cells?

Motor proteins Signup and view all the answers

What ability do cells have in response to stimuli?

Movement toward or away from substances Signup and view all the answers

What kind of information do genes store?

Information for constructing cellular structures Signup and view all the answers

What is one way cells may respond to stimuli?

By altering their metabolism Signup and view all the answers

What role do feedback circuits play in cellular function?

To stabilize the cell's environment Signup and view all the answers

Which statement best describes the components involved in cellular metabolism?

Nucleic acids provide information for product design and proteins perform the construction. Signup and view all the answers

What do all living organisms share according to modern biological tenets?

A common genetic code Signup and view all the answers

Which characteristic distinguishes prokaryotic cells from eukaryotic cells?

Size and complexity Signup and view all the answers

Which feature is common to both prokaryotic and eukaryotic cells?

Plasma membrane Signup and view all the answers

What is the last universal common ancestor often referred to as?

LUCA Signup and view all the answers

What aspect of cellular activity requires constant regulation?

Maintaining complex ordered states Signup and view all the answers

What is the primary location of genetic material in eukaryotic cells?

Nucleus Signup and view all the answers

Which of the following statements accurately describes eukaryotic cells compared to prokaryotic cells?

Eukaryotic cells have more DNA and are more complex. Signup and view all the answers

How do prokaryotic cells primarily reproduce?

Simple fission Signup and view all the answers

What type of organelles are typically absent near the cell membrane in a eukaryotic cell's cytoplasm?

Membrane-bound organelles Signup and view all the answers

What is a key difference regarding ribosomes between prokaryotic and eukaryotic cells?

Eukaryotic ribosomes differ in size and complexity. Signup and view all the answers

Which structure is primarily responsible for locomotion in prokaryotic cells?

Flagella Signup and view all the answers

Approximately how long ago did complex multicellular animals appear in the fossil record?

600 million years ago Signup and view all the answers

What primarily limits cell size?

Distance substances can effectively diffuse Signup and view all the answers

What distinguishes the cytoplasm of eukaryotic cells from that of prokaryotic cells?

Eukaryotic cells have membrane-bound organelles. Signup and view all the answers

What is one goal of Synthetic Biology?

To develop novel life forms using existing organisms Signup and view all the answers

Which of the following describes a virion?

A virus particle outside the host cell containing genetic material Signup and view all the answers

What determines the viral specificity for a certain host?

The virus’ surface proteins Signup and view all the answers

Which type of viral infection leads to the lysis of the host cell?

Lytic infection Signup and view all the answers

What do viroids consist of?

A small, naked RNA molecule Signup and view all the answers

What is the purpose of viral capsids being made from a limited number of proteins?

To conserve genome size Signup and view all the answers

What characterizes the integration type of viral infection?

Integrating its DNA into the host’s chromosomes Signup and view all the answers

What fundamental principle is cell biology based on?

Studying the parts can explain the character of the whole. Signup and view all the answers

Who first coined the term 'cells' while observing cork?

Robert Hooke Signup and view all the answers

According to cell theory, where do cells arise from?

From pre-existing cells through division Signup and view all the answers

What genetic material is crucial for building an organism and is stored within the cell nucleus?

Chromosomes Signup and view all the answers

Which cells are known for their ability to grow and reproduce in culture over extended periods?

HeLa cells Signup and view all the answers

What is the primary genetic programming material that cells utilize?

DNA Signup and view all the answers

What similarity is observed among cells from different species?

They share similar structures and composition. Signup and view all the answers

What does the term 'animalcules' refer to in cell biology?

Microscopic living organisms observed in specimens Signup and view all the answers

Study Notes

Discovery of Cells

Intensive study of cells involves creative tools and techniques.
Cell biology is reductionist, focusing on how studying parts reveals the whole.

Microscopy

Microscopes enabled visualization of cells.
Robert Hooke named the pores he saw in cork "cells," likening them to monk cells.
Antonie van Leeuwenhoek observed "animalcules" in pond water and bacteria from peppercorn.

Cell Theory

Formulated in the mid-1800s by Matthias Schleiden, Theodor Schwann, and Rudolf Virchow.
States: All living organisms are made of cells; the cell is the basic unit of life; cells arise from pre-existing cells.
Additional tenet: Cells contain DNA, which is passed to subsequent generations.

Basic Properties of Cells

Life defines the fundamental property of cells, which can grow and reproduce.
HeLa cells are immortal tumor cells from Henrietta Lacks, used extensively in research.
Cellular processes are highly regulated, with similarities across species in structure and metabolism.

Genetic Programming

Genes, encoded in DNA within the nucleus, direct cellular structure and function.
Can exist as haploid (one set) or diploid (two sets) genetic material.

Cell Reproduction

Involves division, distributing contents from a mother cell to two daughter cells.

Energy Acquisition

Photosynthesis is essential for energy; animal cells primarily utilize glucose.
Energy is stored in ATP, allowing for quick energy release.

Chemical Reactions

Cells function as miniature chemical plants, with enzymes facilitating metabolic processes.
Metabolism encompasses all cellular chemical reactions.

Mechanical Activities

Cells engage in transport, assembly/disassembly of structures, and movement.
Many mechanical functions are driven by changes in the shape of motor proteins.

Response to Stimuli

Cells respond to environmental changes through receptors that interact with hormones and other substances.
Responses may include metabolic alterations, movement, or programmed cell death.

Self-Regulation

Cells maintain stability despite fluctuations through feedback mechanisms.
Coordination of nucleic acids (for design) and proteins (for execution) is crucial.

Evolution of Cells

Origin remains unclear, but evolution studied through current organisms.
All living cells share features like a common genetic code and ribosomes.
All life forms are believed to have evolved from a single ancestral cell, known as LUCA.

Classes of Cells

Two primary classes: Prokaryotic (bacteria) and Eukaryotic (plants, animals, fungi, protists).
Differences include size, organelles, genetic material structure, and complexity.

Distinguishing Characteristics

Prokaryotic cells lack membrane-bound organelles and have simpler structures.
Eukaryotic cells have a nucleus and more complex organelles.

Eukaryotic DNA

Eukaryotes possess larger amounts of DNA compared to prokaryotes.
Complex multicellular organisms appeared suddenly in the fossil record about 600 million years ago.

Eukaryotic vs. Prokaryotic Functions

Eukaryotic cytoplasm contains organelles and denser macromolecular complexes, including ribosomes.
Eukaryotes reproduce through mitosis, while prokaryotes undergo simple fission.

Eukaryotic Cell Crowding

Eukaryotic cell cytoplasm is densely packed, affecting cell functionality.
Size limitations based on supporting cytoplasm volume and diffusion efficiency.

Synthetic Biology

Aims to create living cells in labs, with goals of developing novel organisms for medicine and industry.
Successful genome replacement in bacteria suggests promising applications.

Viruses and Viroids

Viruses act as intracellular obligate parasites, requiring host cells for reproduction.
A virion consists of genetic material and protein subunits, with some having a lipid envelope.

Virus Types and Mechanisms

Bacteriophages exhibit complex infection cycles, showcasing medicinal potential.
Viroids, composed of naked RNA, disrupt host gene expression.

Capsid Structure and Function

Viral capsids consist of a few protein subunits to optimize genome size and specificity.
Virus specificity is determined by surface proteins that bind to host cell receptors.

Viral Infection Types

Lytic infections lead to the host cell's lysis and release of new virions.
Integration infections see the viral DNA becoming part of the host’s chromosomes.

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Description

Explore the fascinating world of cells and their discovery in this quiz. Learn about the important role of microscopy and the contributions of pioneers like Robert Hooke. Test your knowledge on cell biology and its reductionist approach to understanding life's building blocks.