Cells Test 1 Flashcards
Human Biological Science
scientific study of humans, both as individuals and as populations and the study of the interaction between humans and their environment
Cell theory
cells are the building blocks that make up all living organisms
Cell membrane
structure that surrounds to cell and forms the outer boundary of the cell
Cytoplasm
thick fluid that fills the inside of the cell and suspends structures within it
Organelles
structures suspened in cytoplasm that carry out particular functions
Cytosol
the liquid part of the cytoplasm
Cytoskeleton
internal scaffalding of protein fibres within the cytoplasm
Centrioles
The cylindrical structures that are involved in the reproduction of the cell
ER
The parallel membranes, which connect the cell membrane with the nuclear membrane. It provides a surface for chemical reactions to take place. The channels between the paired membranes are used for storage or transport. Smooth/agranular (no ribosomes), Rough/granular (ribosomes)
Ribosomes
Small spheres that join amino acids together to make proteins
Lysosomes
Small spheres that contain enzymes. It breaks down proteins, lipids, nucleic acids and some carbohydrates; breaks down unwanted substances.
Nucleus
Contains genetic material; DNA
Nuclear membrane
Separates nucleus from cytoplasm
Nuclear Pores
The gaps in the nuclear membrane
Nucleolus
Contains RNA
Nucleoplasm
The jelly like substance where DNA and nucleus are stored
Mitochondira
Spherical or elongated structures that release energy for the cell through respiration
Golgi Body
Spherical or elongated structures that release energy for the cell through respiration
Tissue fluid
Is the immediate environment of a cell that surrounds it. This is also known as extracellular fluid
Homeostasis
Body systems that work together to make sure that the cellular environment is kept constant. Maintained at a constant temperature and concentration of fluids
Fluid mosaic model
current model of cell membrane
Phospholipid
lipid molecules containing a phosphate group
Bilayer
two layers of phospholipid
Hyrdophilic
the head of the phospholipid (water-loving)
Hydrophobic
the tail of the phospholipid (water-hating)
Phosopholipid Arrangement
head outside, tail inside
Channel Proteins
from channel through membrane to allow ions, water and molecules pass
Relationship between surface area and volume
As the volume decrease, surface area : volume ratio increases
Functions of a cell
- a physical barrier
- regulation of the passage of materials
- sensitivity
- support
Membrane proteins
- receptor proteins
- channel proteins
- carrier proteins
- cell-identity markers
Transport within cells
passive and active process
Differentially permeable
Allows certain ions and molecules to pass through, but restrict the movement of others.
Passive processes
cell’s energy, which comes from respiration, does not have to be used
Active processes
requires the cell’s energy for the transfer to occur
Diffusion
the spreading out of particles so that they are evenly distributes over the space available
Concerntration gradient or diffusion gradient
the difference in concerntration that brings about diffusion
Osmosis
the diffusion of water molecules through a differentially permeable membrane from an area of higher water concentration to lower water concentration
Osmotic Pressure
The pressure due to different concentrations on either side of differentially permeable membrane
Carrier-meditated transport
transport of ions/molecules across a cell membrane
Facilitated diffusion
carrier proteins assist the movement of substances through a cell membrane
Active Transport
Use of energy to move substances across a cell
Vesicular Transport
transport of materials into or out of a cell membrane in membrane-bound sacs
Vesicles
Membrane-bound sacs
Endocytosis
Cell takes in materials by enfolding/enclosing
Pinocytosis
taking in liquids into cell
Phagocytosis
taking in solid particles into cell
Exocytosis
Contents of vesicles are pushed out through membrane
Differentiation
unspecialised cells develop special characteristics to suit particular functions
Tissue
Group of cells that are similar in function and structure
Organ
Group of tissues working together
System
Group of organs working together in a common function
Organism
A living thing
Epithelium tissue
covering or lining tissue
eg.
lining of lung, stomach, intestine, heart,kidneys,mouth
Connective Tissue
provide support for the body and holds body parts together
eg. cartilage, blood in blood vessels, holds organs in positions, fat storage, bone, ligament
Muscular Tissue
skeletal - muscles in arms and legs
involuntary - involuntary muscles
cardiac - heart
Nervous Tissue
Made up of neurones
eg. brain, spinal cord
Metabolism
All the chemical reactions occurring in a living organism
Catabolism
Chemical reactions that break down large organic molecules into smaller ones, with release of energy
Anabolism/synthesis
Combining smaller molecules to make larger ones; requires energy
Organic compounds
contains carbon
carbohydrates, amino acids, proteins, lipids, nucleic acids
Inorganic compounds
doesn’t contain carbon
water, carbon dioxide, oxygen, minerals
Enzymes
Proteins that allow chemical reactions to take place at normal body temperature
Activation energy
energy needed to get a chemical reaction started
Substrate
A molecule upon which enzymes act
Cellular respiration
organic molecules, taken in as foods, are broken down in the cells to release energy for the cell’s activities. supplies energy
Chemical equation for cellular respiration
Glucose + Oxygen > CO2 + H20 + Energy
C6H12O6 + 6O2 > 6CO2 + 6H20 + energy
Glycosis
First phase of breaking down glucose
Anaerobic respiration
respiration without oxygen
Aerobic respiration
respiration requiring oxygen; 38 molecules
citric acid cycle
formation of two or more ATP molecules from the two pyruvic acid molecules
electron transport system
produce up to 34 molecules of ATP. from the product of one molecule of glucose
nutrients
any substance in foods that is used for growth, repair or maintaining of the body water carbohydrates lipids proteins minerals vitamins
