Organisation - Part 1: Lesson 1 - 6 Flashcards
What are the levels of organization in a multicellular organism?
Organelles → Cells → Tissues → Organs → Organ Systems → Organism
What is an organelle?
An organelle (subcellular structure) is a part of a cell that has a specific function, e.g., nucleus, mitochondria, and ribosomes.
What is a cell?
A cell is the basic unit of life, made up of organelles.
What are examples of specialized cells?
- Epithelial cells – Cover body surfaces (e.g., skin, intestines)
- Muscle cells – Contract and relax to move the body
- Glandular cells – Produce and secrete chemicals like enzymes and hormones
What is a tissue?
A tissue is a group of similar cells that work together to perform a specific function.
Give three examples of tissues and their functions.
- Epithelial tissue – Covers body surfaces (e.g., skin, intestines)
- Muscle tissue – Contracts and relaxes for movement
- Glandular tissue – Produces and secretes substances (e.g., enzymes, hormones)
What is an organ?
An organ is a group of different tissues that work together to perform a particular function.
Give an example of an organ and the tissues it contains.
Stomach (Function: Digests food)
* Epithelial tissue – Covers and protects
* Muscle tissue – Contracts to churn food
* Glandular tissue – Produces digestive enzymes
What is an organ system?
An organ system is a group of organs that work together to carry out a function.
Give an example of an organ system and its function.
Digestive System – Breaks down food and absorbs nutrients. Includes stomach, pancreas, liver, intestines, etc.
Name three other organ systems and their functions.
- Cardiovascular System – Transports blood, oxygen, and nutrients
- Respiratory System – Allows breathing and gas exchange
- Nervous System – Sends and receives messages through nerves
What is the highest level of organization in a living thing?
The organism – a living being with multiple organ systems working together.
What is an enzyme?
An enzyme is a biological catalyst that speeds up chemical reactions without being used up or changed.
Why do cells need enzymes?
Chemical reactions in cells are naturally too slow, and enzymes allow reactions to happen quickly and efficiently.
What is a catalyst?
A catalyst is a substance that increases the speed of a reaction without being changed or used up.
Why are enzymes called biological catalysts?
Because they are catalysts produced by living organisms.
What are enzymes made of?
Enzymes are proteins, made up of long chains of amino acids that fold into a unique shape.
What is a substrate?
A substrate is the reactant in an enzyme-catalyzed reaction.
What is the active site of an enzyme?
The active site is the part of the enzyme with a specific shape that binds to the substrate.
Why is the shape of an enzyme’s active site important?
The active site is complementary to the substrate. If the substrate doesn’t fit, the enzyme cannot catalyze the reaction.
What is the lock and key model?
The lock and key model states that the enzyme’s active site is a perfect fit for the substrate—like a key fitting into a lock.
What is the induced fit model?
The induced fit model states that the enzyme changes shape slightly to make a better fit for the substrate.
Which enzyme model is more accurate?
The induced fit model is more accurate because enzymes adjust their shape to bind more effectively to the substrate.
