Biology Chapter on Cell Structure and Functions

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What condition occurs when fluid loss exceeds intake, resulting in decreased fluid levels?

Edema

Dehydration (correct)

Hyperhydration

Hypertension

Which of the following is NOT a function of electrolytes?

Nerve/muscle function

pH control

Energy storage (correct)

Water movement

Which type of protein primarily has a supportive function in the body?

Antibodies

Hormones

Enzymes

Structural proteins (correct)

What is the storage form of glucose in the body?

Glycogen Signup and view all the answers

Which of the following statements about lipids is true?

They primarily consist of long chains of carbon atoms. Signup and view all the answers

What does the cell theory state about living organisms?

All living things are composed of cells. Signup and view all the answers

Which of the following best describes the primary function of cells?

Metabolism, including nutrient utilization and waste removal. Signup and view all the answers

In what significant way did Robert Hooke contribute to the study of cells?

He was the first to observe and name cells. Signup and view all the answers

What is the role of water in cells?

Functions as a universal solvent and transport medium. Signup and view all the answers

Which statement about cell shapes is accurate?

Shape often indicates the function of the cell. Signup and view all the answers

What is the correct term for the outer cell boundary commonly known as the plasma membrane?

Plasmalemma Signup and view all the answers

Which model describes the structure of the plasma membrane consisting of a lipid bilayer and various proteins?

Fluid mosaic model Signup and view all the answers

Which characteristic allows the plasma membrane to control the passage of molecules?

Selectively permeable barrier Signup and view all the answers

What type of molecules can pass through the plasma membrane via diffusion?

Small uncharged molecules Signup and view all the answers

What process describes the movement of fluid molecules across a membrane to balance osmotic pressure?

Osmosis Signup and view all the answers

Which essential fatty acids are derived from cold-water fish and flaxseed oil?

Omega-3 fatty acids Signup and view all the answers

Which of the following is NOT a function of the plasma membrane?

Energy production Signup and view all the answers

What distinguishes foundational from non-foundational fatty acids?

Presence of double bonds Signup and view all the answers

What role does cholesterol play in cellular structures?

It determines membrane fluidity. Signup and view all the answers

Which of the following correctly describes the nucleus?

It selectively allows substances to enter and exit through its pores. Signup and view all the answers

What is the function of the nucleolus within the nucleus?

Assembles large and small ribosome subunits. Signup and view all the answers

Which component is found in the cytoplasm and plays a critical role in protein synthesis?

Ribosomes Signup and view all the answers

What is the primary role of mitochondria within cells?

Produce ATP molecules. Signup and view all the answers

What describes the cytoskeleton's structure and function?

It has a continuous state of assembly and disassembly. Signup and view all the answers

Which nutrient is essential for DNA synthesis and repair?

Folic Acid (folate) Signup and view all the answers

Which of the following is NOT a function of the cytoplasm?

Ribosome assembly. Signup and view all the answers

What is the primary function of mitochondria in relation to ATP?

Manufacturing ATP through enzyme systems Signup and view all the answers

What role does Carnitine play in relation to mitochondria?

It helps transport long-chain fatty acids to mitochondria. Signup and view all the answers

What distinguishes Rough Endoplasmic Reticulum (rER) from Smooth Endoplasmic Reticulum (sER)?

sER lacks ribosomes and processes proteins made in rER. Signup and view all the answers

What is the primary function of the Golgi apparatus?

Sorting and modifying proteins before secretion. Signup and view all the answers

How does repeated use of certain substances lead to proliferation of Smooth Endoplasmic Reticulum (sER)?

It enhances the detoxification process by creating more sER. Signup and view all the answers

In humans, which cell demonstrates the function of flagella?

Sperm cells Signup and view all the answers

What condition is associated with heteroplasmy and can cause blindness?

Leber’s hereditary optic neuropathy Signup and view all the answers

What type of projections do cilia represent?

Short projections that move in concert Signup and view all the answers

Study Notes

Introduction to Cells

Anatomy is the study of parts
Cells are the basic unit of structure, and their function is needed to understand bodily processes
Examples include respiration, protein synthesis, mitosis, and meiosis.
Diseases originate in cells.
The organizational hierarchy is atom → molecule → organelle → cell → tissue → organ → organ system → organism.
Robert Hooke (17th century) first observed cells through a microscope
Cells were initially named after their resemblance to cubicles in a monastery.
Cell theory (Schleiden & Schwann): all living things are composed of cells, and all cells come from pre-existing cells.
Humans have approximately 60-100 trillion cells derived from a single cell.
Cells exhibit varied shapes and sizes which often correlate with their purpose.
Red blood cells, for example, have thin shapes for efficient gas transport.

Cell Chemistry

Water is the most abundant compound in cells, serving as a universal solvent.
It dissolves many substances.
Dehydration occurs when fluid loss exceeds intake, impacting intra- and extracellular fluid levels.
Electrolytes (acids, bases, salts) are important for water movement, pH control, nerve/muscle function, and enzymatic activity.
Low electrolyte levels can lead to muscle cramps, heart attack, and brittle bones.
Proteins are nitrogen-containing organic compounds, with amino acids as building blocks.
They are essential for both structural support and metabolic functions (e.g., hormones, enzymes).
Carbohydrates (2:1 ratio of H to O) serve as energy sources and building blocks. Monosaccharides are simple sugars, disaccharides combine two, and polysaccharides chain many together. These provide fuel and storage (glycogen).
Lipids (fats and related substances like cholesterol) are crucial for energy storage, insulation, and membrane structure.

Cell Structure

The cell membrane (plasmalemma) is the outer boundary of all cells, acting as a selectively permeable barrier.
The fluid mosaic model describes it's structure as two lipid layers with embedded proteins.
Water loving ("hydrophilic") parts of the molecules are on the outer layer.
Water fearing ("hydrophobic") parts of the molecules are on the inner layer.
The membrane is selectively permeable, enabling certain substances to pass through.
Small uncharged molecules and lipid-soluble substances diffuse easily, but other substances require active transport ("osmosis").
Cells use osmosis to move water from areas of low solute concentration to areas of high solute concentration.
Cellular functions include transport, nutrition, attachment to other cells, and communication through enzymatic reactions.
Examples of important fatty acids include Omega-3, Omega-6, and Omega-9.

Nucleus

The nucleus is the largest single membrane-bound structure, enclosed by a nuclear envelope with pores.
It controls cell functions via DNA, and assembles ribosomes (in nucleolus).
Cells synthesize DNA, and DNA supports protein synthesis.
Folic acid is crucial for DNA synthesis and repair.

Cytoplasm

Cytoplasm (also known as cytosol) is the material between the nucleus and the plasmalemma, mostly fluid.
It houses essential components like protein synthesis, protein degradation, and carbohydrate metabolism systems.
Ribosomes are the sites of protein synthesis.
The cytoskeleton provides a protein scaffold to support and organize cellular structures.

Organelles (Mitochondria, ER, Golgi)

Mitochondria produce energy (ATP) via respiration or metabolic processes.
Endoplasmic reticulum (ER) is a network of tubules. Rough ER has ribosomes for protein synthesis. Smooth ER for lipid synthesis and detoxification.
Golgi apparatus receives, processes, and packages proteins and lipids for secretion or use within the cell.
Cell structures (cilia and flagella) protrude from a cell surface, helping with movement or material transport.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on cell structure, fluid balance, and the functions of various biomolecules. This quiz covers important concepts related to cells, including their boundaries, functions, and the role of electrolytes. Dive deep into the world of biology with these essential questions.