Cell Anatomy & Physiology 1 Flashcards
What is the cell theory?
- The cell is the smallest unit of life
- All organisms are made up of one or more cells
- Cells only arise from other cells
The general composition of cell
plasma membrane, cytoplasm, organelles, and nucleus.
4 main functions of cell
- cell metabolism
- sysnthesis of molecules
- communication
- reproduction and inheritance
refers to all the chemical reactions that happen in cells to convert food into energy. Essentially, it’s how cells turn what we eat into the fuel they need to function.
Cell metabolism and energy use
the process where cells create new substances by putting smaller parts together. For example, cells can combine simple sugars to make more complex sugars or build proteins from amino acids. It’s like assembling building blocks to form something new and useful for the body.
Synthesis of molecules
how cells send and receive messages to coordinate their actions.They use signals, like hormones or proteins, to share information with each other. This helps cells work together, respond to their environment, and maintain balance in the body.
Communication
Cells contain a copy of genetic information to be passed of by future generations
Reproduction and inheritance
has phospholipid bilayer and fluid quality to allow phospholipid to move and boundary between materials in and out of the cell
Plasma Membrane
What is the structure of cell membrane called?
fluid mosaic model
most membrane lipids are ________ but 20% is ________
phospholipid ; cholesterol
helps stiffen the plasma membrane
cholesterol
make up about half of plasma membrane and are responsible for specialized functions
Membrane Proteins
Two types of membrane proteins
integral & peripheral
embedded in the membrane, most are transmembrane proteins
Integral proteins
not embedded ; loosely attached and has hydrophobic region
Peripheral proteins
Intergral protein functions are:
transport channels, carriers, enzymes, receptor/signal transducer
Peripheral protein functions are:
structural support, enzymes, motor proteins, linking cells
are integral proteins that allow ions or molecules to pass through
Transport proteins
refers to their ability to selectively move certain molecules or ions across cell membranes.
Specificity
happens when different molecules try to use the same transport protein to enter or exit a cell.
Competition
refers to the point at which all available transport proteins in a cell are fully occupied with molecules.
Saturation
- are glycoproteins have have an exposed receptor side and used as an intercellular communication and coordination system with specificity that specific cellular responses only get triggered by specific signals
Receptor proteins
allows immune system to recognize pathogens
Receptor proteins
can catalyze reactions in or out the surface of plasma membrane
Enzymes
are special proteins that help speed up chemical reactions in the body. They act like tools or helpers that make it easier for reactions to happen, allowing our cells to function efficiently.
Enzymes
populate the extracellular surface of plasma membrane and are attached to most membrane proteins forming glycoproteins and some membrane form glycolipids
Carbohydrates
collection of glycolipids, glycoproteins, and other carbohydrates on the outer surface of plasma membrane
Glycocalyx
Molecules and substances in the plasma membrane can move in two ways:
Passive and Active
does not require require energy and involves diffusion of molecules along concentration gradient
Passive transport
requires energy due to movement of molecular physiology against concentration gradient
Active transport
the movement of molecules or ions from one area of higher concentration to a lower one
Diffusion
the greater the difference in concentration, the faster the diffusion
Concentration
smaller molecules diffuse more rapidly
Molecular size
higher temperature increases the energy available and thus, the speed of diffusion increases
Temperature
- substances readily dissolve
- includes: gasses, steroid hormones, and fatty acids
Simple diffusion
criteria to determine how easily substances will diffuse
lipid solubility and size
- bigger lipid molecules can’t pass through bilipid layer
- bigger molecules like sugar and amino acid can be carried by carrier proteins
- ions and water can pass through channel proteins, depending on size and charge
Facilitated Diffusion
- diffusion of solvent through selectively permeable membrane
- movement of water molecules through a cell membrane from an area where there’s a lot of water to an area where there’s less water. It happens naturally, without using energy
Osmosis
refers to the total concentration of all solutes particles dissolved in a solution
Osmolarity
the ability of a solution to change the shape of cells by changing the cell’s internal water volume
Tonicity
Tonicity: retains its size
Isotonic
Tonicity: shrinks
Hypertonic
Tonicity: becomes bloated and bursts
Hypotonic
- occurs when a cell uses energy to move solutes
- typically for substances too large to pass through channels, lipid insoluble materials or moving them against a concentration gradient
Active transport
uses energy from ATP by transport called pumps
Primary active transport
driven by energy stored in concentration of ions created by the primary pumps, uses cotransport protein
Secondary active transport
Uses cotransport
Secondary active transport
important in various physiologic functions like muscle contraction and nerve stimulation
Primary active transport
Three types of passive transport
Simple diffusion, facilitated diffusion and osmosis
