Anatomy and Physiology Sem 01

What are the three main parts of a generalized cell?

Plasma membrane, cytoplasm, nucleus

What is the plasma membrane?

A selectively permeable membrane that surrounds the cell and controls movement of substances in and out

What is the cytoplasm?

The region between the plasma membrane and nucleus containing cytosol and organelles

What is the nucleus?

The organelle that contains DNA and controls cellular activities

What are organelles?

Specialized structures within cells that perform specific functions

What is the nucleolus?

A region within the nucleus where ribosomes are produced

What are ribosomes?

Structures that synthesize proteins

What is the rough endoplasmic reticulum?

Endoplasmic reticulum with ribosomes that synthesizes proteins

What is the smooth endoplasmic reticulum?

Endoplasmic reticulum without ribosomes that synthesizes lipids and detoxifies substances

What is the Golgi apparatus?

An organelle that modifies, sorts and packages proteins and lipids

What are mitochondria?

Organelles that produce ATP through cellular respiration

What are lysosomes?

Organelles containing digestive enzymes that break down waste and cellular debris

What is the cytoskeleton?

A network of protein filaments that maintains cell shape and aids movement

What are the three types of cytoskeleton filaments?

Microfilaments, intermediate filaments, microtubules

What is the fluid mosaic model?

A model describing the plasma membrane as a fluid lipid bilayer with embedded proteins

What is the phospholipid bilayer?

A double layer of phospholipids forming the basic structure of the cell membrane

Why is the cell membrane selectively permeable?

It allows some substances to pass while restricting others

What are membrane proteins used for?

Transport, receptors, enzymes, cell recognition and adhesion

What is diffusion?

The movement of molecules from an area of high concentration to low concentration

What is facilitated diffusion?

Passive movement of substances across the membrane using transport proteins

What is osmosis?

The diffusion of water across a selectively permeable membrane

What is active transport?

The movement of substances across a membrane using energy (ATP)

What is a concentration gradient?

A difference in concentration between two areas

What is endocytosis?

The process by which a cell takes substances into the cell via vesicles

What are the two main types of endocytosis?

Phagocytosis and pinocytosis

What is phagocytosis?

The engulfing of large particles or cells

What is pinocytosis?

The uptake of extracellular fluid and dissolved substances

What is receptor-mediated endocytosis?

Endocytosis that uses receptor proteins to selectively bring substances into the cell

What is exocytosis?

The process by which materials are released from the cell via vesicles

What is metabolism?

The sum of all chemical reactions occurring in a cell

What are metabolic pathways?

A series of chemical reactions where the product of one reaction becomes the substrate for the next

What is an enzyme?

A biological catalyst that speeds up chemical reactions without being consumed

What is a substrate?

The molecule that an enzyme acts upon

What is the active site of an enzyme?

The region where the substrate binds and the reaction occurs

What is the induced fit model?

A model where the enzyme changes shape slightly to fit the substrate

What factors affect enzyme activity?

Temperature, pH, substrate concentration and enzyme concentration

What is denaturation?

The loss of an enzyme’s shape and function due to extreme conditions

What is anabolism?

Metabolic reactions that build complex molecules

What is catabolism?

Metabolic reactions that break down molecules and release energy

What is cellular respiration?

The process by which cells produce ATP from nutrients

Why is ATP important in metabolism?

It provides energy for cellular processes