Biology Chapter: Cell Functions and Structures

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Questions and Answers

Which of the following is NOT a primary function of cells?

Metabolism

Creating new organisms (correct)

Maintaining homeostasis

Producing hormones

What is the significance of the cell theory, as proposed by Schleiden and Schwann?

It proved that all living organisms are made up of cells. (correct)

It established the role of the nucleus in cell function.

It demonstrated the existence of cells for the first time.

It explained the process of cell division.

Based on the text, which of these is NOT a major component of the organizational hierarchy of life?

Atoms

Organelles

Organisms

Ecosystems (correct)

Why are red blood cells (RBCs) typically thin and flat in shape?

To maximize surface area for gas exchange. Signup and view all the answers

What is the significance of water being the most abundant compound in cells and the extracellular environment?

It facilitates the movement of substances within the cell and between the cell and its surroundings. Signup and view all the answers

Which of the following is NOT a function of electrolytes?

Production of energy Signup and view all the answers

What is the primary function of structural proteins?

Providing support and structure Signup and view all the answers

Which of these is a characteristic of lipids?

They are essential for the formation of cell membranes Signup and view all the answers

What is a common source of dehydration?

Vomiting and diarrhea Signup and view all the answers

Which of the following is NOT a true statement about carbohydrates?

They are essential for the formation of cell membranes Signup and view all the answers

What is the main structure of the plasma membrane?

Lipid bi-layer Signup and view all the answers

Which statement correctly describes the fluid mosaic model of the plasma membrane?

It contains two layers of lipid molecules with embedded proteins. Signup and view all the answers

What type of molecules can pass through the plasma membrane due to its selectively permeable nature?

Small uncharged molecules Signup and view all the answers

What is the process called when fluid molecules move across a membrane to equalize solute concentration?

Osmosis Signup and view all the answers

Which of the following is a function of the plasma membrane?

Transport and communication Signup and view all the answers

Which fatty acid is commonly sourced from cold-water fish and flaxseed oil?

Omega-3 Signup and view all the answers

Omega-6 fatty acids are primarily derived from which type of food sources?

Vegetable oils and nuts Signup and view all the answers

What term describes the outer layer of the plasma membrane that interacts with water?

Hydrophilic Signup and view all the answers

What is the primary function of cholesterol in the cell membrane?

To increase membrane fluidity Signup and view all the answers

What role does the nucleolus play within the nucleus?

It assembles ribosome subunits Signup and view all the answers

Which nutrient is essential for DNA synthesis and repair?

Folic Acid Signup and view all the answers

What is the function of the cytoskeleton?

It provides structural support and facilitates transport within the cell Signup and view all the answers

Which statement about mitochondria is true?

They have a folded inner membrane known as cristae Signup and view all the answers

What is the composition of the nuclear envelope?

Adjacent membranes surrounding the nucleus Signup and view all the answers

Which component is primarily responsible for protein synthesis in cells?

Ribosomes Signup and view all the answers

In which structure is the cytoplasm found?

Between the nucleus and the cell membrane Signup and view all the answers

What is the primary function of Carnitine in the body?

Transport of long-chain fatty acids to the mitochondria for energy production Signup and view all the answers

Where are the enzymes responsible for ATP production located within a cell?

Mitochondria Signup and view all the answers

Which of the following processes is NOT carried out by the smooth endoplasmic reticulum (sER)?

Production of proteins secreted by the cell Signup and view all the answers

What is the significance of all mitochondria in an embryo being maternally inherited?

It ensures that all offspring inherit the same mitochondrial DNA from their mother Signup and view all the answers

What is the likely cause of Leber's hereditary optic neuropathy?

Inheritance of a large number of abnormal mitochondria (heteroplasmy) Signup and view all the answers

Study Notes

Human Anatomy - Cytology

Anatomy studies the structure of body parts
Cells are the basic units of structural organization
Proper body function relies on cell function
Understanding cell processes (respiration, protein synthesis, mitosis, meiosis) is key
Diseases originate in cells
Cells organize hierarchically: atoms → molecules → organelles → cells → tissues → organs → organ systems → organism
Robert Hooke (17th century) first observed cells in cork
Cells were named for monastery cubicles
Cell theory (Schleiden & Schwann): all living things are made of cells, the cell is the basic unit of structure in all organisms
All cells come from existing cells

Cell Chemistry

Water is the most abundant compound in cells and the extracellular environment
Water acts as a universal solvent
It transports substances across membranes and within cells
Dehydration occurs when fluid loss exceeds intake
Electrolytes are inorganic compounds that form ions in water.
These ions (acids, bases, salts) are important for:
- Water movement
- pH balance
- Nerve and muscle function
- Enzyme activity
Low electrolyte levels can cause muscle cramps, heart failure, and brittle bones.
Proteins are nitrogen-containing organic compounds.
Proteins are formed from 20+ different amino acids.
Proteins have structural and functional roles (support, enzymes, hormones)
Carbohydrates have a 2:1 ratio of Hydrogen to Oxygen
Types of carbohydrates include monosaccharides, disaccharides, and polysaccharides
These serve as energy sources and storage molecules.

Cell Structure

The cell's outer boundary is the plasma membrane (plasmalemma)
It's a lipid bilayer with various proteins
The outer layer is hydrophilic (water-loving) and the inner layer is hydrophobic (water-fearing)
The structure is called a "fluid mosaic model" which is made up of two layers of lipid molecules
The membrane is selectively permeable allowing some substances into cells and expelling others.
Water moves to equalize concentration across a membrane (osmosis)
Proteins within the membrane vary in structure and mobility, affecting its function
Cells are constantly being assembled and disassembled
Functions include anchoring organelles, cell communication
Cells transport molecules across their environment

Other Cellular Structures

Organelles: Membrane-bound structures within cells (e.g., mitochondria, ribosomes). They have specific functions.
Mitochondria: Produce energy (ATP), found in most cells
Endoplasmic Reticulum (ER): Involved in protein synthesis and lipid production. Rough ER is studded with ribosomes and plays a role in protein secretion, whereas Smooth ER plays a role in lipid metabolism.
Golgi apparatus: Processes proteins and lipids, sorting them for transport.
Ribosomes: Sites of protein synthesis
Cilia and Flagella: Cytoplasmic projections that assist in movement. Cilia is short and Flagella is longer. (cilia move substances over the surface of cells or tissues; flagella power movement of the whole cell like sperm)

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Test your understanding of cell functions, the significance of cell theory, and the components of life organization. This quiz covers essential concepts related to cell structure, proteins, lipids, and water's role in biological systems. Dive in to see how well you grasp these foundational topics in biology.